alimov-7-algebra-gdz (Алгебра - 7 класс - Алимов), страница 5

1) a 4b6c2 = a 2b3c ;3) 49 x8 y 622) x 2 y 4 z8 − xy 2 z 4)2(4) 100c8 x 6 = 10c4 x 3;187. 1) (0,25) ⋅ 47 = (0,25 ⋅ 4) = 1 ;77⎛ 4⎞⎝ 5⎠17⎛ 5⎞⎝ 4⎠172) ⎜ ⎟ ⋅ ⎜ ⎟)2⎛ 4 5⎞=⎜ ⋅ ⎟⎝ 5 4⎠17=13) ( −0,125) ⋅ 811 = ( −0,125 ⋅ 8) = −1 ; 4) ( −0,2) ⋅ 55 = ( −0,2 ⋅ 5) = −111188. 1)3)189. 1)3828 ⋅ 385610525 ⋅ 55==81 ⋅ 273831128 ⋅ 38552 ⋅3105105== 23 ⋅ 33 = 216 ;= 1;34 ⋅ 3983=52)4)31383= 243 ;2)4 5 ⋅ 3512=314423 ⋅ 73=( )28 ⋅ 7 2147512 5121441434=3= 12 2 = 144 ;= 14 .148147= 14 ;3)16 2 ⋅ 3 512 4⎛ 2⎞⎝ 3⎠2190.

1) ⎜ ⎟ =⎛ 3⎞⎝ a⎠4 4 ⋅ 35==3;4 4 ⋅ 344)2=5 329 ⋅ 21022) ⎜ − ⎟ =9a2215=219215= 24 = 16 .25;493b3⎛b⎞4) ⎜ ⎟ =512⎝8⎠;44a4⎛ a ⎞191. 1) ⎜ ⎟ =;16b 4⎝ 2b ⎠81b4⎛ 3b ⎞⎟ =⎝ 5c ⎠625c42) ⎜73⎛ 23 ⎞2213) ⎜⎜ 2 ⎟⎟ = 14 ;3⎝3 ⎠⎛ 52 ⎞564) ⎜⎜ 4 ⎟⎟ = 127⎝7 ⎠3(a + b) ;⎛ a + b⎞⎟ =⎝ 3 ⎠272) ⎜5(m + n) ;⎛ m + n⎞⎟ =⎝ m − n⎠(m − n)54) ⎜3249⎛ 7 ⎞⎟ =⎝ 2 + c⎠( 2 + c) 2192. 1) ⎜7( a + b)⎛ a + b⎞⎟ =⎝ a − b⎠( a − b)7573) ⎜375⎛ 5⎞⎝ 7⎠4;93) ⎜ − ⎟ =( )(2 )29 ⋅ 22753193. 1)25 ⎛ 2 ⎞m3 ⎛ m ⎞57 ⎛ 5 ⎞⎛ 3⎞=;2)=3)=;4)=⎜ ⎟⎜⎟⎜⎟⎜⎟23 ⎝ 2 ⎠a7 ⎝ a ⎠47 ⎝ 4 ⎠55 ⎝ 5 ⎠194. 1)( 2a )2(3b)22)( 4 x )4( 3 y )44)−1 ⎛ 1 ⎞= ⎜− ⎟27 ⎝ 3 ⎠2⎛ 2a ⎞=⎜ ⎟ ;⎝ 3b ⎠33)1 ⎛ 1⎞= ⎜− ⎟ ;−8 ⎝ 2 ⎠⎛ 4x ⎞=⎜ ⎟⎝ 3y ⎠74339195. 1) 4n ⋅ 45 = 4n +5 ;3) c28 ⋅ cn = c28+ n ;2) 38 ⋅ 3n = 38+ n4) a n ⋅ a13 = a n +13196.

1) y n ⋅ y m = y n + m ;2) bn ⋅ b k = bn + k3) 54 k ⋅ 54 = 54 k + 4 ;4) 33n ⋅ 33m = 33n + 3m197. 1) 22n : 2n = 2n ;2) 23n : 22 n = 2n .4) 2 4 n + 5 : 2 n + 2 = 2 3n + 33) 24 n +1 : 22n = 22 n +1 ;198. 1) 34n : 33n = 3n ;2) 36n : 32n = 34 n3) 3n + 3 : 3n +1 = 32 ;4) 3n + 6 : 3n + 2 = 34 .199. 1) 3n = 9 при n = 2;( )3) 2200. 1)3)2 n2) 128 = 2n при n = 7( )4) 3n= 16 при n = 2;612 ⋅ 412312 ⋅ 8122412=15434 ⋅ 52 ⋅ 252412=3344= 1;15434 ⋅ 52 ⋅ 5222)=154154= 1 ; 4)32= 81 при n = 2.410 ⋅ 310210 ⋅ 610416810232=2=23012101210=1= 22 = 4 .32435⎛ 35 ⎞ ⎛ 6 ⎞ ⎛ 3 ⎞⎛ 35 ⋅ 6 ⎞ ⎛ 8 ⎞⎛5⎞ ⎛8⎞⎟ ⋅ ⎜ ⎟ ⋅ ⎜1 ⎟ = ⎜⎟ ⋅⎜ ⎟ = ⎜ ⎟ ⋅⎜ ⎟ =8⎝ 48 ⎠ ⎝ 7 ⎠ ⎝ 5 ⎠⎝ 48 ⋅ 7 ⎠ ⎝ 5 ⎠⎝8⎠ ⎝5⎠201. 1) ⎜432⎛ 14 ⎞ ⎛ 3 ⎞⎛ 14 ⋅ 3 ⎞ ⎛ 5 ⎞⎛ 2⎞ ⎛ 5⎞3⎟ ⋅ ⎜ ⎟ ⋅ (2 ,5) = ⎜⎟ ⋅⎜ ⎟ = ⎜ ⎟ ⋅⎜ ⎟ =⎝ 15 ⎠ ⎝ 7 ⎠⎝ 15 ⋅ 7 ⎠ ⎝ 2 ⎠⎝ 5⎠ ⎝ 2⎠52) ⎜4⎛ 53 ⎞ ⎛ 2 ⎞ 5 ⎛ 3 ⎞ 7 512 ⋅ 25 ⋅ 37113) ⎜⎜ 2 ⎟⎟ ⋅ ⎜ ⎟ ⋅ ⎜ ⎟ = 8 8 12 ==3243 ⋅ 2 ⋅53⋅ 2⎝ 6 ⎠ ⎝ 5 ⎠ ⎝ 5⎠3⎛ 74 ⎞ ⎛ 5 ⎞ 6 ⎛ 3 ⎞ 5 712 ⋅ 56 ⋅ 35 714) ⎜⎜ 2 ⎟⎟ ⋅ ⎜ ⎟ ⋅ ⎜ ⎟ = 6 6 11 = = 2 .333 ⋅5 ⋅ 7⎝ 15 ⎠ ⎝ 7 ⎠ ⎝ 7 ⎠202.

1) x 2 = 0,25;x 2 = 400;61⎛1⎞x 6 = (0,25)3 = ⎜ ⎟ =64⎝2⎠x 6 = (400 )3 = 640000001 100x 2 = 11 =;994031000000⎛ 100 ⎞x6 = ⎜⎟ =9729⎝⎠2) x 3 = 0,008;x 6 = 0,000064x3 = 125;x6 = 15625x3 = 3x 2 = 37203. 1)2729⎛ 27 ⎞x6 = ⎜ ⎟ =64⎝ 8 ⎠3 27=;8 81 1000=;27272 ⋅ 10306 ⋅ 1024=21000000⎛ 1000 ⎞x6 = ⎜⎟ =27729⎝⎠106= 333333,(3) (раз).3Ответ: масса солнца больше земли в 333333,(3) раза.2) S = 83000000000000 км. Vсвета ≈ 300000 км/с =30000001080000000== 300000 ⋅ 3600 км/ч =км/сутки =1: 36001: 24= 25920000000 км / сутки =8300000≈ 8,8 года.2592 ⋅ 365Ответ: примерно 8,8 года.204. 1) 310 = 590493) (2,3)4 = 27,98412) 59 =19531254) (1,3)5 = 3,71293205.

1) 544 и 21122) 1020 и 2010544 = 312 ⋅ 242112 = 312 ⋅ 712712 > 24 ⇒ 544 < 21121020 = 220 ⋅ 5202010 = 220 ⋅ 5103) 10020 и 9000104) 620 и 340 620 = 320 ⋅ 220(100)20 = 1040 = 1010 ⋅ 1030340 = 320 ⋅ 320(900010 = 9 ⋅ 103)105 20 > 510 ⇒ 10 20 > 2010320 > 220 ⇒ 340 > 620= 910 ⋅ 1030910 < 1010 ⇒ 10020 > 900010206. 1)2)2 ⋅ 5 22 − 9 ⋅ 5 2125105 ⋅ 232 − 4 ⋅ 230416==5 21 ⋅ (2 ⋅ 5 − 9)(5 )2 105 ⋅ 232 − 232232==5 215 20=5;232 ⋅ (5 − 1)232=4;413)(4 ⋅ 322)− 7 ⋅ 321 ⋅ 57(19 ⋅ 27 )4 2=(22)()⋅ 322 + 7 ⋅ 321 ⋅ 57 321 ⋅ 2 2 ⋅ 3 + 7 ⋅ 57==19 2 ⋅ 32419 2 ⋅ 33419 ⋅ 57 1=192 ⋅ 32 95 ⋅ 3 ⋅ 715 − 19 ⋅ 714714 ⋅ 5 ⋅ (3 ⋅ 7 − 19 ) 5 ⋅ 2 14)===16157 ⋅ 10 77 + 3⋅7715 ⋅ (7 + 3)=()§ 11. Одночлен. Стандартный вид одночлена207.

1) m3 p ;2) 3a 2b ;3) 3600t ;(опечатка в ответе задачника).4) 100n0,5b2 = 0,5 ⋅ ( −4) = 0,5 ⋅ 16 = 82208. 1) b = −42) a = 2; b =11; c=231 13abc = 3 ⋅ 2 ⋅ ⋅ = 12 3209. 1) Одночлены стандартного вида:10,2a 2b2c; − 7 ,3ab2c4 ; − 2 ,6ab2c3 ; − m; 3ab; − 28a 2b2c2 ; 17a 2b2c22) Одночлены, отличающиеся только коэффициентами:−28a 2b2c212и 17a 2b2c2 3ab и −2a b210. 1) 3m4m = 3m5 ;2) z5 ⋅ z5 ⋅ z = z11( )4) ( − m) ⋅ − m3 = m43) −ab ⋅ 0,5 = −0,5ab ;5) 5 pq ( −4) qp = 400 p q ;6) 2 pq ( −3) pq = 72q 2 p37) −2 ,5m( −0,8)m3n4 = 2m4n4 ;8)2222 3133222 2 ⎛ 2⎞4xy ⋅ ⎜ − ⎟ xy = − x 2 y 3⎝ 11⎠333⎛ 1⎞ ⎛ 1 ⎞⎝ 3⎠ ⎝ 6 ⎠162211.

1) При a = − ; c = − : ac ⋅ 12c = 12ac2 = 12 ⋅ ⎜ − ⎟ ⋅ ⎜ − ⎟ = −122) При a = −2; b = :212. C = 2πRS = πR 21) При R = 37 ,5423314 ⎛ 1⎞a ⋅ 8b2 ba 3 = a 4b3 = ( −2) ⋅ ⎜ ⎟ = 2⎝ 2⎠46, )(π ≈ 314C = 2 ⋅ 314, ⋅ 37 ,5 ≈ 235,519S = 3,14 ⋅1,3 2 ≈ 5,3066 ≈ 5,31C 122,46=≈ 19,5R=2π 2 ⋅ 3,142) При R = 1,33) При C = 122 ,464) При C = 16,4πC 2 C 2 (16,4)⎛ C⎞S = π ⋅⎜ ⎟ ==≈≈ 21,414012 ≈ 21,4⎝ 2π ⎠4π 2 4π 4 ⋅ 3,1422§ 12. Умножение одночленов()3) ( 4a ) ⋅ ( 6a ) = 24a(213.

1) (2 p) ⋅ −3c2 = −6 pc2 ;235)2) −5m2 ⋅ ( −7n) = 35m2n⎛ 1⎝ 2⎞⎠( )4) ⎜ − b3 ⎟ ⋅ 8b2 = −4b5;( )( )2) ( 7a b c) ⋅ ( −3ab c) = −21a b c214. 1) 3a 2b5c ⋅ 6a 3bc2 = 18a 5b6c3 ;5 246 6 2⎞⎠⎞ ⎛3⎠ ⎝4⎛2⎝33) ⎜ a 3b3 x⎟ ⋅ ⎜ a 3bx 2 ⎟ =⎛ 3⎝ 2⎞ ⎛3⎠ ⎝4⎞1 5 4 3ab x2984) ⎜ − a 3 xy3 ⎟ ⋅ ⎜ ax 2 y ⎟ = − a 4 x3 y 4⎠⎞⎠⎛ 1⎝ 3215. 1) ⎜ − m2 ⎟ ⋅ ( −24n) ⋅ (4mn) = 32m3n2⎛ 1⎝ 6⎞⎠2) ( −18n) ⋅ ⎜ − m2 ⎟ ⋅ ( −5nm) = −15m3n2()1 4 3 4⎞⎞ ⎛3⎛1a x y3) ⎜ ay 3 ⎟ ⋅ ⎜ x 2 y ⎟ ⋅ 0,2a 3 x =20⎠⎠ ⎝4⎝3()()()4) −13a 2bc ⋅ −5ab2c ⋅ −0,4abc3 = −26a 4b4c5( )216.

1) (2a ) = 8a 3 ; 3) 3b23( )3) (− 3x y )3217. 1) −2a 2b = −8a 6b3 ;33= 9x 6 y 2 ;4( )= 81b8 2) (5b) = 25b2 ; 4) 2a 32( )4) ( −2 x y )2= 4a 652) − a 2bc = − a10b5c52 3 4= 16 x8 y1243⎞⎠⎛1⎝2318218. 1) ⎜ m2n⎟ = m6n3 ;()3) −0,1a 3b3 = −0,001a 9b9 ;()2= 0,16a 6b42322⎞⎠1 8 8mn813) −0,2bc2 ⋅ 20cx 2 = 0,8b2c5 x52) ( − a ) ⋅ (2a ) = −2a 4 ;⎞ ⎛ 1⎠ ⎝ 24() ( )4) ( −0,1ab c) ⋅ (100by ) = a b c y235⎞⎠4) 0,4a 3b2219. 1) ( −2a ) ⋅ ( −3a ) = −12a 3 ;⎛⎝⎛1⎝32) ⎜ n2m2 ⎟ =3215220. 1) ⎜ −1 x 3 y 2 ⎟ ⋅ ⎜ − c2 x 2 ⎟ = x 9 y 2c6⎞⎠⎞ ⎛2⎠ ⎝3⎛ 1⎝ 422) ⎜ 2 x 3 y⎟ ⋅ ⎜ xy 2 ⎟ = x5 y5( ) ( ) = −27c ⋅ 4a b = −108a b c4) ( −2a b) ⋅ ( − a b ) = 4a b ⋅ ( − a b ) = −4a b3) −3bc3 ⋅ 2ab22222 3 362 44 22 4 66 910 1155) ( m 2 n) 2 (6mn 2 ) 2 = 25m 6 n 6636) ( m 3 n) 2 (−7mn 2 ) 3 = −21m 9 n 871 25a ⋅ 3a 2b = a 4b при a = −2; b = :37553( −2)4 ⋅ = 16 ⋅ = 117772232) mn ⋅ 10n = 4mn при m = 0,8; n = 4:5221.

1)4 ⋅ 0,8 ⋅ 43 = 204 ,8⎛1 ⎞⎝5 ⎠222. 1) S = ⎜ a ⎟ ⋅ (10b) = 2ab ;⎛ 1 ⎞⎝ 3 ⎠223. 1) V = (0,25m) ⋅ ⎜ 1 n⎟ ⋅ (6mn) = 2m2n2( )2) V = (0,1a ) ⋅ 2b2 ⋅ (5ab) = a 2b344⎛3 ⎞⎝7 ⎠2) S = ⎜ x⎟ ⋅ (14 y ) = 6 xy2 5 2 2( )4) 81x y = ( 9 x y ) ;6) 1,21a b = (11,a b )2224. 1) 9a 2 = (3a ) ;2(3) 25a 2b4 = 5ab22) 16 x 4 = 4 x 2 ;)2(6 2)25) 36 x10 y 4 = 6 x5 y 2 ;( )4) 8a b = ( 2a b )2) 8b6 = 2b2)33) 27a 3b12 = 3ab4 ;9 635)4 2 28 4225. 1) 27 a 3 = (3a )3 ;(231 9 12 ⎛ 1 3 4 ⎞x y =⎜ x y ⎟ ;⎠⎝512533 2 3(6) − 0,027 x 3 y 15 = − 0,3xy 5)3226. 1) (2a ) = 32a 5 при n = 5n⎛ 1⎝ 3⎞⎠n2) ⎜ − x 2 y⎟ = −()1 6 3x y при n = 327n3) 0,2 y 2 ⋅ 100 = 4 y 4 при n = 2⎛ 1⎝ 3⎞⎠n4) ⎜ 3 m4 ⎟ ⋅ 0,001 =1 12m при n = 3271= a 2 b 6 при n = 20,091 12 61 2 n6) (− b c) =b c при n = 66425) (0,3ab 3 ) n ⋅§ 13. Многочлены227.

1) 6 x 2 + 7 x + 9 ;3) − x 4 + x 3 − x5) 8a 3 + 4a 2b − 2ab2 + b3 ;2) 2 x 2 − 11x + 3 ;4) a5 − a 4 + a ;6) 4a 3b − 2a 2b2 − 5ab3228. 1) 12a 2 3ba − 2ab3ab2 + 11aba = 36a 3b − 6a 2b3 + 11a 2b2) 2ab2 4ab − 3a 2 8aba − 2abab2 = 8a 2b3 − 24a 4b + 2a 2b33) 15, xy 2 ( −4) xyz − 4mnk 5m2nk = −6 x 2 y 3z − 20m3n2 k 2⎛ 1⎞⎝ 4⎠4) 4cc2c ⋅ ⎜ − ⎟ bc + 5xy 2 xy 2 = − c5b + 5x 2 y 445229. 1) 2a 4 − ab + 2b 2 при a = −1; b = −0,5:2( −1) − ( −1) ⋅ ( −0,5) + 2( −0,5) = 2 − 0,5 + 0,5 = 2422) x 2 + 2 xy + y 2 при x = 1,2; y = −1.2: (1,2) − 2 ⋅ (1,2) + ( −1,2) = 02212230. 1) − aba + a 2b2ab + 4 = − a 2b + 2a 3b2 + 4 при a = 2; b = :−4 ⋅11+ 2 ⋅8⋅ + 4 = 624152) b2 5ab − 5a5a 2b = 5ab3 − 25a 3b при a = ; b = −2 :3123⎛ 1⎞35 ⋅ ⋅ ( −2) − 25 ⋅ ⎜ ⎟ ⋅ ( −2) = −8 + = −7⎝ 5⎠5553) x 2 yxy − xy 2 xy + xy = x 3 y 2 − x 2 y 3 + xy при x = −3; y = 2:−27 ⋅ 4 ⋅ ( −9) ⋅ 8 − 6 = −108 − 72 − 6 = −1864) xy 2 x 2 y − xyxy = x 3 y 3 − x 2 y 2 при x = −2; y = 3:(− 2)3 ⋅ 3 3 − (− 2)2 ⋅ 3 2 = −8 ⋅ 27 − 4 ⋅ 9 = −216 − 36 = −25237231.

– 0,2 x ⋅ 3x + 7 x ⋅ 1 + 0,1x 2 ⋅ 6 − 2 x = 18 x = 1 ; −0,6 x 2 + 10 x + 0,6 x 2 − 2 x = 1 ; x =Ответ: при x =1818232. 1) 2ab + 3b2 + 1 > 0 всегда, т.к. ab > 0,b2 > 02) a 2 − b2 < 0 если a < b233. 1) b2 − 4a 2 > 0 , если b > 4a2) ab − a 2b2 = ab(1 − ab) > 0 , если a ⋅ b < 1234. Пусть груш было собрано х кг., тогда яблок – 5х кг., а слив –(5х – 350) кг.5x + x + (5x − 350) = 1410 ; 11x = 1410 + 350 ; 11x = 1760x = 160 (кг.) груш было собрано; 160 ⋅ 5 = 800 (кг.) яблок былособрано; 800 – 350 = 450 (кг.) слив было собрано.Ответ: 160 кг.; 800 кг.; 450 кг.46§ 14.

Приведение подобных членов3 4 1 4 1 4 1 4 48 − 2 + 1 − 8 47y − y +y − y =⋅ y = 1 y42163243232351324 − 10 + 2 − 3 2132) a 2b − a 2b + a 2b − a 2b =a b = a 2b288161616235. 1)236. 1) 2m + q + q − 4m = 2q − 2m ;2) 3a + 2b − b − a = 2a + b3) x 2 + 3 y 2 + 4 x 2 − y 2 = 5x 2 + 2 y 24) 5a 2 − 4b2 − 3a 2 + b2 = 2a 2 − 3b2237. 1) 11x 2 + 4 x − x 2 − 4 x = 10 x 2 ;2) 2 y 2 − 3 y + 2 y − 2 y 2 = − y3) 0,3c2 − 0,1c2 − 0,5c3 = 0,2c2 − 0,5c3 ;4) 1,2a 2 + 3,4a 2 − 0,8a 2 = 3,8a 21 2 121x − y + x2 + y = x2 ;33331 2 3 2 4 2 3 22) a + b + a − b = a 25454238. 1)3) 2ab + 0,7b2 − 5ab + 1,2b2 + 8ab = 1,9b2 + 5ab4) 5xy − 3,5 y 2 − 2 xy + 1,3 y 2 − xy = 2 xy − 2,2 y 2239. 1) 2a 2b − 8b2 + 5a 2b + 5c2 − 3b2 + 4c2 = 7a 2b − 11b2 + 9c22) 3xy 2 + 4 x 3 − 5x 2 y − 3x 3 + 4 x 2 y − 9 xy 2 = x 3 − x 2 y − 6 xy 2240.

1) 2m 4n − 3a 2b − 0,2n5m + b5a − 5nm + 8ab = 8mn − 6ab −−mn + 5ab − 5nm +8ab = 2mn + 7ab2) 13ab − 0,2 xy − 2a5b + 6 x(0,2 ) y + a(−3)b = 13ab − 10ab −−3ab − 0,2 xy + 1,2 xy = xy2 ⎛ 3⎞57bc − 2 ab⎜ − ⎟a = 10a 2 bc + a 2 bc + a 2 b =3) 2abc5a + 1 a 23 ⎝ 8⎠712= 11a 2bc + a 2b1⎞23 ⎛ 2⎞⎛4) 3mnk 4n − nm⎜ 2 ⎟nk + n 2 m⎜ − 4 ⎟k =2⎠98 ⎝ 3⎠⎝= 12mn 2 k − n 2 mk − n 2 mk = 10n 2 mk47241. 1) −0,08 x + 73xy 2 + 27 xy 2 = −0,08 x + 100 xy 2 ; при x = 4; y = 0,2:−0,08 ⋅ 4 + 100 ⋅ 4 ⋅ 0,04 = −0,32 + 16 = 15,6813342) −2a 2b + 4b + 11a 2b = 9a 2b + 4b ; при a = − ; b = 2 :2333113⎛ 1⎞9 ⋅ ⎜ − ⎟ ⋅ 2 + 4 ⋅ 2 = 2 (4 + 1) = ⋅ 5 = 13⎝ 3⎠44444242.

1) 2 x 2 − 3x − x 2 − 5 + 2 x − x 2 + 10 = 15 − x = 1; x = 42) 0,3x 2 − x 2 + x − x 3 + 3x 2 + 0,7 x 3 − 2 x 2 + 0,07 = 1x + 0,07 = 1 ; x = 0,93243. 1. 1) 17 + 2 + 1 = 20 (частей) − состовляет 400 кг. бронзы2) 400 : 20 = 20 (кг.) − приходится на одну часть металла3) 20 ⋅ 17 = 340 (кг.) − меди4) 20 ⋅ 2 = 40 (кг.) − цинка5) 20 ⋅ 1 = 20 (кг.) − оловаОтвет: 340 кг., 40 кг., 20 кг.32. Pучастка = 60 м. = 6000 см.4P = 5 + 4 + 3 = 12 (см.)M = 12 см : 6000 см. = 1 : 5005Ответ: масштаб 1 : 500.§ 15. Сложение и вычитание многочленов244. 1) 8a + ( −3b + 5a ) = 8a − 3b + 5a = 13a − 3b2) 5x − (2 x − 3 y ) = 5x − 2 x + 3 y = 3x + 3 y = 3( x + y )3) (6a − 2b) − (5a + 3b) = 6a − 2b − 5a − 3b = a − 5b4) (4 x + 2) + ( − x − 1) = 4 x + 2 − x − 1 = 3x + 1⎛ 3⎝ 534⎞⎠⎛1⎝43 ⎞5 ⎠35343512245.