mordkovitch-gdz-7-2003_1-1145 (542425), страница 7
Текст из файла (страница 7)
Деление одночлена на одночлен№ 348а) a3 : a2 = a; б) y20 : y18 = y2; в) x8 : x3 = x5; г) z54 : z50 = z4.51№ 34911а) x : 3 = x;395 ⎛ 25 ⎞7в) a : ⎜ − ⎟ = − a ;7 ⎝ 49 ⎠510 111=y:y;11 50513 ⎛ 26 ⎞ 1г) − b : ⎜ − ⎟ = 1 b .15 ⎝ 45 ⎠2б)№ 350а) – 8x : (– 4x) = 2; б) 3c : c = 3; в) 7a : (– a) = – 7;№ 351а) 6x3 : x2 = 6x;в) – 15z8 : z8 = – 15;б) – 27y2 : (– 9y2) = 3;г) – 90p4 : (– 5p) = 18p3.№ 352а) – 19a : (– 19a) = 1;в) – 100cd : 20cd = – 5;б) – 45b : (– 15b) = 3;г) 18dy : 6dy = 3.№ 353а) 16abc : 8a = 2bc;в) – 42cdm : 12c = – 3,5dm;г) – 9b : (– b) = 9.б) 24pqr : ( – 4pq) = – 6r;г) – 99xyz : (– 9x) = 11yz.№ 354а) 4,8axy : 1,6xy = 3a;б) (– 8,8abc) : 1,1b = – 8ac;12в) – 0,81pqs : 0,009pq = – 90s; г) 6,4xz : (–1,3z) = – 4 x.13№ 355а) 18a12 : 6a4 = 3a8;в) 12a7y4 : 6a2y3 = 2a5y;1010б) 24b : 6b = 4;г) 6b5x3 : 3b3x2 = 2b2x.№ 356а) 44a3b2c6 : 11a2bc5 = 4abc;б) 198x4y4z2 : 2x4y3z = 99yz;8 9 42 76 2 3в) 144m n r : 12m n r = 12m n r ; г) 258p8q4r17 : 3p6q2r15 = 86p2q2r2.№ 357а) некорректно; б) корректно; в) некорректно; г) корректно.№ 358а) нет; б) да; в) да; г) нет.№ 359а) 30x5y6z7 : 6x2y4z = 5x3y2z6; б) 75a8b11c31 : 5a3b4c10 = 15a5b7c21;в) p11m6q16 : p3m2q7 = p8m4q9; г) d2n3z10 : dnz5 = dn2z5.№ 360а) (5a2b2)3 : (5ab)2 = 125a6b6 : 25a2b2 = 5a4b4;б) (10x3y3)4 : (2x4y3)2 = 10000x12y12 : 4x8y6 = 2500x4y6;в) ( 49z10t14) : (7zt)0 = 49z10t14 : 1 = 49z10t14;г) (– x2y3z)4 : xyz = x8y12z4 : xyz = x7y11z3.52№ 361а) (2m2n2)4 : (4mn)2 = 16m8n8 : 16m2n2 = m6n6;б) 55p3q4 : (5pq)0 = 55p3q4 : 1 = 55p3q4;в) (– x2y3z4)5 : (– xyz)6 = x10y15z20 : x6y6z6 = x4y9z14;г) (– 5ac3d)3 : (5cd)2 = – 125a3c9d3 : 25c2d2 = – 5a3c7d.№ 362а)б)в)г)(2cy 3 ) 2 ·8c5 y2(4c y )3=3 4 3(9a b )(3a 2b)2 ·27 a 4b9(3 x 2c3 ) 2 ·9 x15c 42(3x c)54c 2 y 6 ·8c5 y6 364c y=3 2 3(−2a b )32c7 y 7729a b9a 4b 2 ·27 a 4b9=6 364c y9 12=(7 a 3b3 ) 2 ·(− a 2b)3=9 x 4c 6 ·9 x15c 45 10 53 x c92 ·3a8b1134 x19c1035 x10c549a 6b6 ·(− a 6b3 )9 6−8 a b1 4cy ;293 a9b12==== 3ab;=1 9 5xc;349a12b9=8a9b61= 6 a3b3..8ГЛАВА 4.
Многочлены.Операции над многочленами§ 13. Основные понятия№ 366а) 3a + 4b – многочлен;в) 5(5x2 – 12y2) – многочлен;б) 5x2 – 3y2 – многочлен;г) (a +1)(b – 2) – многочлен.№ 367а) 5x2 – 6x2 +в)1– не многочлен;xb2ab+ 12z2 –– многочлен;45б)3a 2b4ab 2– не многочлен;г) 0,3p2 + 13p – 1 – многочлен.№ 368а) 3x2 + 5y +7– не многочлен;cб)a8 b 6c4d3–++– многочлен;4579102511в) 9x3 – 4y2 – 5 – многочлен;г)№ 369а) 5a + 8a2 – 2,5ab;б) 5a – 4ab + 8a2 – 2,5ab;в) 5a – 4ab + 8a2; 12a – 2,5ab – a2;г) 5a – 4ab +z5+z3+z2–18a 2z1– многочлен..53№ 370а) 0,5x2 + 12xy + 4xy2; б) 0,5x2y – xy2 – 3xy2;в) 0,5x2y – xy2 + 12xy; –3x2y – 0,2xy + 4xy21– 0,2xy.г) 12xy – 3x2y +4xy 2№ 371а) 5x2–3x2 – x3 = 2x2 – x3;б) 1,2c5 + 2,8c5 – 4c5;в) 7y3 + y3 + 12y3 = 20y3;г)1 n 1 n 1 n 1 nd – d + d = d.2363№ 372а) 5x2 – 3xy – 2xy = 5x2 – 5xy;б) 7a2b – 5a2b + ab2 + 2ab2 = 2a2b + 3ab2;в) 3t2 – 5t2 – 11t – 3t2 + 5t + 11 = –5t2 – 6t + 11;г) z3 + 2z2 + z3 – 4z – z2 = 2z3 + z2 – 4z.№ 373а) 4b2 + a2 + 6ab – 11b2 – 6ab = –7b2 + a2;б) 3a2x + 3ax2 5a3 – 3ax2 – 8a2x – 10a3 = –5a2x – 5a3;в) 9x3 – 8xy – 6y2 – 9x3 – xy = – 9xy – 6y2;г) m4 – 3m3n + n2m2 – m2n2 = m4 – 3m3n.№ 374а) m · m · m · m – n · n · n = m4 – n3;б) pq · pq – qp · qp = (pq)2 – (qp)2 = (qp)2 – (qp)2 = 0;в) 3s · 2r + 2rs + 4r · 8s = 6rs + 2rs + 32rs = 40rs;г) 12m · 2n – 3m · 4n – 7m · 8n = 24mn – 12mn – 56mn = –44mn.№ 375а) 4p3 · 2p+3p2 · 4p+2p2 · 2p2 – 2p3 · 4 = 8p4 + 12p3 + 4p4 – 8p3=12p4 + 4p3;б) y · 2y – 3y – y2 – 5 + 2y · y – y · 5 + y · 7y2 == 2y2 – 3y – y2 – 5 + 2y2 – 5y + 7y3 = 7y3 + 3y2 – 8y – 5;2118 234111x+ x+0,8x – x · x – x =x +x + x – x2–x= x2+x;3461212562205111г) 5/6a · a 1/3a – 0,6a · a + a · 0,1a = a2 + a 0,6a2 + 0,1a2 = a + a2.6333в) x ·№ 376а) 2x · 4y – 3x · 2y – 0,2x · 5y + y · 5x – 5xy + 8xy == 8xy – 6xy – xy + 5xy – 5xy + 8xy = 9xy;б) x · p · x · x – p · 3px – p · 4x3 + 7p · x · p == x3 · p – 3p2 · x – 4x3 · p + 7p2 · x = 4p2 · x – 3x3 · p;в) 7x⋅a⋅x+a · 2a⋅x+x · 9x · a–8a · x · a=7x2 · a+2a2x+9x2a–8a2x=10x2a– 6a2x;г) 15r3s – s · r · s · r2 – 3s · r · r · r + 2r2 · s · r = 15r3s – 5r3s + 2r3s = 9r3s.54№ 377а) 15p + 18p2 + 4 – 12p + 3p2 – p4 = –p4 + 21p2 + 3p + 4;б) 1,4x2 – 4,1x3 + x – 3,1 + x + 1,3x3 = –2,8x3 + 1,4x2 + 2x – 3,1;133723 2 57– a=–a –a+ ;в) a + a2 – a2 +4548320128г) 0,2y4 – 3,5y – 1,2y4 – 1 + 3,5y = – y4 – 1.№ 378а) a3b + a2b – 3ab + 2a2b + 2ab2 = a3b + 3a2b + 2ab2 – 3ab;при а = – 1; b = 2; (– 1) 3 · 2 + 3 · (– 1) 2 · 2 + 2 · 1 · 22 – 3 · (– 1) · 2 == – 2 + 6 + 8 + 6 = 18;1152б) x – y3 + 0,3x – x + y2 = – 0,2x + y2;2399232 ⎛3⎞17; – 0,2 · 5 +· ⎜ ⎟ =–1+=– ;49 ⎝4⎠88в) m4 – 3m3n + m2n2 – m3n – 4m2n2 = m4 – 4m3n – 3m2n2;при x = 5; y =4322111 ⎛ 1⎞⎛ 1⎞⎛ 1⎞ ⎛1⎞– 3 · ⎜− ⎟ · ⎜ ⎟ ;; y = ; ⎜− ⎟ – 4 · ⎜− ⎟ ·23 ⎝ 2⎠3⎝ 2⎠⎝ 2⎠ ⎝3⎠22323222г) 6p q – 5pq + 5p + 2pq – 8p – 3p q = 3p q – 3pq – 3p3.при m = –№ 379а) x3 + 2x2 + 7x + 8x – x3 – x2 – x2 = 15x; 15x = 1; x =Ответ:1.51.5б) 0,5y3 + 2,7y2 + 3,5y + 6,5y – 0,5y3 – 2y2 – 0,7y2 = 10y; 10y = 1; y =1.101.1042в) 3z – z + 4z + z + z2 – 2z4 – z4 + 8 = 5z + 8; 5z + 8 = 1; 5z = – 7;72z = – ; z = –1 .55Ответ: – 1,4г) 6p3 – p2 + 4p3 + p2 – 10p3 – 3p + 19 = – 3p + 19;–3p + 19 = 1; 3p = 18; p = 6.Ответ: 6.Ответ:№ 3803a + 11; a = 5x + 4;11 + 3(5x + 4) = 11 + 15x +12 = 15x + 23.55№ 38114 – 8a; a = 3x2 – 4x + 2;14 – 8(3x2 – 4x + 2) = 14 – 24x2 + 32x – 16 = – 24x2 + 32x – 2.№ 38211а) c · c – 0,1c5 – c3 + c · c2 · 2c2 – c · c + c · c · c =281 21413= c –0,1c5–c3 + 2c5 – c2 + c3 = 2c5 – 0,1c5 + c2 – c2=1,9c5 + c2;2888811111б) m · m–m · m · m+0,5m+m · m · 1/8m–1/3m2 + m= m2– m3+922921 3 13 3 12 38 3 1 3 1 2+ 0,5m + m + m =m –m –m + m + m +m=822424249917 3 1 2= −m +m + m;924в) aba + aa – a · 2ab + bab – 2ba · 2b – 6a · 2b2 – aa== a2b + a2 – 2a2b + ab2 – 4b2a – 12ab2 – a2 = – a2b – 15ab2;г) y · 2yy – y · 5xy + x· 3xy – xy · 6y + x · 12xy – y3== 2y3 – 5xy2 + 3x2y – 6xy2 + 12x2y – y3 = y3 – 11xy2 + 15x2y.№ 383а) 12m · 0,2 m3 + 3,5m · 2m – 27 + 4,5m2 · 0,2m – 15m == 2,4m4 + 7m2 – 27 + 0,9m3 – 15m = 2,4m4 + 0,9m3 + 7m2 – 15m – 27;б) 3,6r · 5r2 – 0,4r2 · 7r + 1,4r3 – 10r2 · 2r + 15r · 0,5r2 == 18r4 – 2,8r3 + 1,4r3 – 20r3 +7,5r3 = 18r4 – 13,r3;в) 9a3 · 0,3a – 12a · 0,4a2 + 7a · 0,2a3 + 1,7a2 · (– 3a) – 13a · 0,5a == 2,7a4 – 4,8a3 + 1,4a4 – 5,1a3 – 6,5a2 = 1,3a4 – 9,9a3 – 6,5a2;г) 0,5b · 4b2 – 5b · 0,3b – 3b2 · (–0,2b) + 14b2 · 0,5 – 25b · 0,3b2 = 2b3 –– 1,5b2 + 0,6b3 + 7b2 – 7,5b3 = – 4,9b3 + 5,5b2.№ 384а) 5a–13+8a–7a + 25 + (– 6a) = 12; б) 7b–15+10a – 2a + 13 – 8a = 7b – 2;в) 12a–23+2a–3a + b + (– 11a) = b – 23; г) 8a2 – 7a2 – 4 + (– a2) = – 4.№ 385а) a2 + 2a2 – b2 – 3c + (– 3a2) = – b2 – 3c;б) 3ax2 – 5x3 +4a2 + 8x2a2 – 5 + 11a2 + (– 15a2 = 3ax2 – 5x3 + 8x2a – 5; в)2x2 + 3ax – 9a2 + 8x2 – 5ax + 8a2 + a2 = 10x2 – 2ax;г) 2y2 – 5ay + a2 + 7y2 + 3ay – 5a2 + 4a2 = 9y2 – 2ay.№ 386а) 7x + 4y – 11; y = 3x2 – 12x + 5;7x + 4(3x2 – 12x + 5) – 11 = 7x + 12x2 – 48x + 20 – 11 = 12x2 – 41x + 9;б) 13a + 6b – 7; b = 4 – a2 + 3a;13a + 6(4 – a2 + 3a) – 7 = 13a + 24 – 6a2 + 18a – 7 = – 6a2 + 31a + 17.56№ 387Пусть x = 3a +12; y = 13 – a; z = 5 +4a;а) x + y + z = 3a + 12 +13 – a + 5 + 4a = 6a + 30;б) x – y + z = 3a + 12 – 13 + a + 5 + 4a = 8a + 4;в) y – x + z = 13 – a – 3a – 12 + 5 + 4a = 6;г) z – x – y = 5 +4a – 3a – 12 – 13 + a = 2a – 20.№ 388Пусть a = 3x2 + 4x + 8; b = 1,2 – 2x2 – 7x; c = 12,5x2 – 3,5x + 21,8;а) a+b+c=3x2+4x+8+1,2–2x2 – 7x + 12,5x2 – 3,5x + 21,8=13,5x2 – 6,5x + 31;б) a–b+c=3x2 + 4x + 8–1,2+2x2+7x + 12,5x2–3,5x+21,8=17,5x2+7,5x + 28,6;в) b–a–c=1,2–2x2–7x–3x2–4x–8 – 12,5x2 + 3,5x – 21,8=–17,5x2–7,5x – 28,6;г) c– b–a=12,x2–3,5x+21,8–1,2+2x2 + 7x – 3x2 – 4x – 8=11,5x2 – 0,5x + 12,6.№ 389Пусть R = 5a3 + 4a2b + 8ab2 – 24b3, L = 7a3 – 13a2b – 4ab2 + 17b3,m = –12a3 + 9a2b – 4ab2 + 15b3;а) R + L + m = 5a3 + 4a2b + 8ab2 – 24b3 + 7a3 – 13a2b – 4ab2 + 17b3 ++ (– 12a3) + 9a2b – 4ab2 + 15b3 = 8b3;б) L + R – m = 7a3 – 13a2b – 4ab2 + 17b3 + 5a3 + 4a2b +8ab2 – 24b3 ++ 12a3 – 9a2b + 4ab2 – 15b3 = 24a3 – 18a2b + 8ab2 – 22b3;в) m – L – r = – 12a3 + 9a2b – 4ab2 + 15b3 – 7a3 + 13a2b + 4ab2 – 17b3 –– 5a3 – 4a2b – 8ab2 + 24b3 = – 24a3 + 18a2b – 8ab2 +22b3;г) L – R + m = 7a3 – 13a2b – 4ab2 + 17b3 – 5a3 – 4a2b – 8ab2 + 24b3 –– 12a3 + 9a2b – 4ab2 + 15b3 = – 10a3 – 8a2b – 16ab2 + 56b3.§ 14.
Сложение и вычитание многочленов№ 390Найдите P(a) = P1(a) + P2(a), еслиа) P1(a) = 2a + 5; P2(a) = 3a – 7; P(a) = 2a + 5 + 3a – 7 = 5a – 2;б) P1(a) = 7 – 2a; P2(a) = – 1 – 5a; P(a) = 7 – 2a – 1 – 5a = – 7a + 6;в) P1(a) = 3a – 4; P2(a) = 11 – 3a; P(a) = 3a – 4 + 11 – 3a = 7;г) P1(a) = – 4 – 3a; P2(a) = 7 – 8a; P(a) = – 4 – 3a + 7 – 8a = 11a + 3.№ 391Найдите P(x) = P1(x) + P2(x), если :а) P1(x) = 2x3 + 5; P2(x) = 3x3 + 7; P(x) = 2x3 + 5 + 3x3 + 7 = 5x3 + 12;б) P1(x) = 6x2 – 4; P2(x) = 5x2 – 10; P(x) = 6x2 – 4 + 5x2 – 10 = 11x2 – 14;в) P1(x)=4x5+2x+1; P2(x)=x5+x–2; P(x)=4x5+2x+1+x5+x–2=5x5 + 3x – 1;г) P1(x)=x11+x6–3; P2(x)=2x11+3x6+1; P(x)=x11+x6–3+2x11+3x6+1=3x11+4x6 – 2.№ 392Найдите P(a,b) = P1(a,b) +P2(a,b)а) P1(a,b) = a + 3b; P2(a,b) = 3a – 3b;P(a,b) = a + 3b + 3a – 3b = 4a;б) P1(a,b) = a2 – 5ab – 3b2; P2(a,b) = a2 + b2;57P(a,b) = a2 – 5ab – 3b2 + a2 + b2 = 2a2 – 5ab – 2b2;в) P1(a,b) = 8a3 + 3a2b – 5ab2 + b3; P2(a,b) = 18a3 – 3a2b – 5ab2 + 2b3;P(a,b) = 8a3+3a2b–5ab2 + b3 + 18a3 – 3a2b – 5ab2 + 2b3=26a3 – 10a2b +3b3;г) P1(a,b) = 10a4 – 7a3b – a2b2 + 6; P2(a,b) = 17a4 – 10a3b + a2b2 + 3;P(a,b) =10a4 – 7a3b – a2b2 + 6 + 17a4 – 10a3b + a2b2 + 3 = 27a4– 17a3b + 9.№ 393Найдите P(y) = P1(y) – P2(y), если:а) P1(y) = 2y2 + 8y – 11; P2(y) = 3y3 – 6y + 3;P(y) = 2y2 + 8y – 11 – 3y3 + 6y – 3 = – 3y3 + 2y2 + 14y – 14;б) P1(y) = 4y4 + 4y2 – 13; P2(y) = 4y4 – 4y2 + 13;P(y) = 4y4 + 4y2 – 13 – 4y4 + 4y2 – 13 = 8y2 – 26;в) P1(y) = y3 – y + 7; P2(y) = y3 + 5y +11;P(y) = y3 – y + 7 – y3 – 5y – 11 = – 6y – 4;г) P1(y) = 15 – 7y2; P2(y) = y3 – y2 – 15;P(y) = 15 – 7y2 – y3 + y2 + 15 = – y3 – 6y2 + 30.№ 394Найдите P(c,d) = P1(c,d) – P2(c,d), если:а) P1(c,d) = 3c2 + d; P2(c,d) = 2c2 – 3d;P(c,d) = 3c2 + d – 2c2 + 3d = c2 + 4d;б) P1(c,d) = 5c4 + 3c2d – d3; P2(c,d) = 2c2 – 3c2d + d2;P(c,d) = 5c4 + 3c2d – d3 – 2c2 + 3c2d – d2 = 5c4 + 6c2d – d3 – d2 – 2c2;в) P1(c,d) = 12c2d – 3cd2 + 4; P2(c,d) = 6c2d – 5cd2 + 2c;P(c,d) = 12c2d – 3cd2 + 4 – 6c2d + 5cd2 – 2c = 6c2d + 2cd2 – 2c + 4;г) P1(c,d) = c2 + 2cd + d2; P2(c,d) = 5c2 – 6cd – 7d2;P(c,d) = c2 + 2cd + d2 – 5c2 + 6cd + 7d2 = – 4c2 + 8cd + 8d2.№ 395а) (5x – 3) + (7x – 4) = 8 – (15 – 11x);5x – 3 + 7x – 4 = 8 – 15 + 11x; 12x – 11x = – 7 + 7; x = 0.Ответ: 0.б) (4x + 3) – (10x + 11) = 7 + (13 – 4x); 4x + 3 – 10x – 11 = 7 + 13 – 4x;4x – 10x + 4x = 20 + 11 – 3; – 2x = 28; x = – 14.Ответ: –14.в) (7 –10x) – (8 – 8x) + (10x +6) = – 8; 7 – 10x – 8 + 8x + 10x + 6 = – 8;8x = – 8 – 6 + 8 – 7; x = –135; x=–1 .8858Ответ: – 1 .г) (2x + 3) + ( 3x + 4) + (5x + 5 ) = 12 – 7x;2x + 3 + 3x + 4 + 5x + 5 = 12 – 7x;10x + 7x = 12 – 12; 17x = 0; x = 0.Ответ: 0.58№ 3963910⎛5⎞а) y – ⎜ y − 1, 25 ⎟ = 0,55;y–y + 1,25 = 0,55;41212⎝6⎠11y = 0,55 – 1,25; –y = – 0,7; y = 8,4.–1212Ответ: 8,4.398⎛1⎞x – ⎜ x − 2, 4 ⎟ = – 0,4;x–x + 2,4 = – 0,4;382424⎝⎠11x = – 0,4 – 2,4;x = – 2,8;x = – 67,2.2424б)Ответ: – 67,2.в)3x – (0,25x – 3) = 1,2; 0,75x – 0,25x + 3 = 1,2; 0,5x = – 1,8; x = – 3,6.4Ответ: – 3,6.г)1x – (2,5x – 3) = 1,8; 0,5x – 2,5x +3 = 1,8; – 2x = – 1,2; x = 0,6.2Ответ: 0,6.№ 397а) x – 1; б) (x – 0,5) + (x – 1) + (x – 1,5) = 3x –3;в) x + x – 0,5 = 2x – 0,5; г) x + (x – 0,5) + (x – 1) + (x – 1,5) = 4x – 3.№ 398P1(a) = 2a3 + 3a3 – a + 1; P2(a) = 4a4 + 6a3 – 2a2 + 2a;P3(a) = 2a5 + 3a4 – a3 + a2;а) P1(a) + P2(a) + P3(a) = 2a3 + 3a3 – a + 1 + 4a4 + 6a3 – 2a2 + 2a ++ 2a5 + 3a4 – a3 + a2 = 7a3 + 2a2 + a + 1 + 7a4 + 2a5;б) P1(a) – P2(a) + P3(a) = 2a3 + 3a3 – a + 1 – 4a4 – 6a3 + 2a2 – 2a ++ 2a5 + 3a4 – a3 + a2 = 2a5 – a4 – 5a3 + 6a2 – 3a + 1;в) P1(a) + P2(a) – P3(a) = 2a3 + 3a3 – a + 1 + 4a4 + 6a3 – 2a2 + 2a –– 2a5 – 3a4 + a3 – a2 = – 2a5 – 3a4 + a3 – a2;г) P1(a) – P2(a) – P3(a) = 2a3 + 3a3 – a + 1 – 4a4 – 6a3 + 2a2 – 2a – 2a5 –– 3a4 + a3 – a2 = – 2a5 – 7a4 – 3a3 + 4a2 – 3a + 1.№ 399P1(x,y) = 27x3 – 27x2y + 9xy2 – y3; P2(x,y) = 20x3 – 15x2y + 4xy2 – 3y3;P3(x,y) = 10x3 + 12x2y – 5xy2 + y2;а) P(x,y) = P1(x,y) + P2(x,y) + P3(x,y) = 27x3 – 27x2y + 9xy2 – y3 ++ 20x3 – 15x2y + 4xy2 – 3y3 + 10x3 + 12x2y – 5xy2 + y2 == 67x3 – 30x2y + 8xy2 – 4y3 + y2;б) P(x,y) = P1(x,y) – P2(x,y) + P3(x,y) = 27x3 – 27x2y + 9xy2 – y3 –– 20x3 + 15x2y – 4xy2 + 3y3 + 10x3 + 12x2y – 5xy2 + y2 == 17x3 + 10x2y + 2y3 + y2;59в) P(x,y) = P1(x,y) + P2(x,y) – P3(x,y) = 27x3 – 27x2y + 9xy2 – y3 ++ 20x3 – 15x2y + 4xy2 – 3y3 – 10x3 – 12x2y + 5xy2 – y2 == 37x3 – 44x2y + 18xy2 – 4y3 – y2;г) P(x,y) = P1(x,y) – P2(x,y) – P3(x,y) = 27x3 – 27x2y + 9xy2 – y3 –– 20x3 + 15x2y – 4xy2 + 3y3 – 10x3 – 12x2y + 5xy2 – y2 == – 3x3 – 24x2y + 10xy2 + 2y3 – y2.№ 400а) 2x2 – (2x2 – 5x) – (4x – 2) = 5;2x2 – 2x2 + 5x – 4x + 2 = 5; x = 5 – 2; x = 3.Ответ: 3.б) 3y3 – (3y3 – 6y) – (3y + 4) = 2;3y3 – 3y3 + 6y – 3y – 4 = 2; 3y = 6; y =2.Ответ: 2.в) (x2 – 7x – 11) – (5x2 – 13x – 18) = 16 – 4x2;x2 – 7x – 11 – 5x2 + 13x + 18 = 16 – 4x2;x2 – 5x2 + 4x2 – 7x + 13x = 16 – 18 +11; 6x = 9; x = 1,5.Ответ: 1,5.г) (y2 – 5y – 19) – (5y2 – 6y – 9) = 26 – 4y – 4y2;y2 – 5y – 19 – 5y2 + 6y + 9 = 26 – 4y – 4y2;y2 – 5y2 + 4y2 – 5y + 6y + 4y = 26 – 9 + 19; 5y = 36; y =7,2.Ответ: 7,2.№ 401Второй столбец4x + 10– 4mn– 2c2d – 3cd2 + 8а) 9x + 7 – 5x – 6 = 4x + 1;б) a3 + 2a2b + b3 – a3 – 2a2b – b3 = 0;в) m2 – 2mn + n2 – m2 – 2mn – n2 = – 4mn;г) 0 – 2c2d – 3cd2 + 8 = – 2c2d – 3cd2 + 8.№ 402а) 6a2 – (2 – (1,56a – (a2 + 0,36a)) + (5,5a2 + 1,2a – 1)) == 6a2 – (2 – 1,56a + a2 + 0,36a + 5,5a2 + 1,2a – 1) == 6a2 – a2 – 5,5a2 + 1,56a – 0,36a – 1,2a – 2 + 1 = 0,5a2 – 1;б) (a2 + 2x2) – (5a2 – 1,2ax + (2,8x2 – (1,5a2 – 0,5ax + 1,8x2))) == a2 + 2x2 – (5a2 – 1,2ax + (2,8x2 – 1,5a2 + 0,5ax – 1,8x2)) == a2 + 2x2 – (5a2 – 1,2ax + 2,8x2 – 1,5a2 + 0,5ax – 1,8x2) == a2 + 2x2 – 5a2 + 1,2ax – 2,8x2 + 1,5a2 – 0,5ax + 1,8x2 == a2–5a2 +1,5a2 + 2x2 – 2,8x2 + 1,8x2 + 1,2ax – 0,5ax=– 2,5a2 + x2 + 0,7ax;в) 12,5x2 + y2 – (8x2 – 5y2 – ( – 10x2 + (5,5x2 – 6y2))) == 12,5x2 + y2 – (8x2 – 5y2 – ( – 10x2 + 5,5x2 – 6y2)) == 12,5x2 + y2 – (8x2 – 5y2 + 10x2 – 5,5x2 + 6y2) == 12,5x2 + y2 – 8x2 + 5y2 – 10x2 + 5,5x2 – 6y2 == 12,5x2 – 8x2 – 10x2 + 5,5x2 + y2 + 5y2 – 6y2 = 0;60г) (y3 + 3z2) – (y3 – 6az + (2y3 – (3z2 + 4az – 1,2y3))) == y3 + 3z2 – (y3 – 6az + (2y3 – 3z2 – 4az + 1,2y3)) == y3 + 3z2 – (y3 – 6az + 2y3 – 3z2 – 4az + 1,2y3) == y3 + 3z2 – y3 + 6az – 2y3 + 3z2 + 4az – 1,2y3 == y3 – y3 – 2y3 – 1,2y3 +3z2 + 3z2 +6az + 4az = – 3,2y3 + 6z2 + 10az.§ 15.
![](https://s.studizba.com/z.php?f=/templates/si/i/noavatar.png&w=100&h=100&t=1"){kind=avatar}
