整式旳加减 5 0题(有答案)(1) 7-3x-4 x2+4x-8 x 2-15 (2) 2(2 a2-9b)-3(-4 a2+b) (3) 8 x2-[-3x-(2 x 2-7x-5)+3]+4 x(4)(5)(6)-3 (7)-(8) (9)(10)(2 x-3 y)+(5 x+4y) (11)(8a-7b)-(4 a-5 b)(12)a-(2 a+b)+2(a-2b) (1 3)3(5x+4)-(3 x-5)(14)x+[x+(-2 x-4 y)] (15)(a+4b)- (3a-6 b)(16)3 x2-1-2 x-5+3 x-x2 (17) (a+4b)- (3 a-6 b) (18)4x+2y—5x—y (19)—3ab+7—2a 2—9 ab—3(20)7x 2-2x+3 x-7 x2 (21)-0
8 a 2b-6ab-1
2a2b+5ab+a2b(22) (23)6x2y+2 x y-3x 2y 2-7 x-5 y x-4 y 2x2-6x2y(24)8x+2y+2(5x-2y) (2 5)3 a-(4b-2a+1)(2 6)7 m+3(m+2n) (27)(x 2-y2)-4(2 x 2-3y 2)(28)-4 x+3( x-2) (29)5(2x-7y)-3 (4x-3 y)(30)(31) (32)(33) (34)(35) (36)(37) (38)(3x-5y)-(6x+7y)+(9x-2y)(39)-1-7 x+3 x-7 x2 (40)(4 1)-3(2x3y-3x 2y2+3x y3) (42)(43)4 x 2y-8 xy 2+7-4x 2y+12x y2-4 (4 4)a 2-2 a b+b 2+2 a2+2a b - b2(45)先化简,再求值:,其中
(46)化简:. (47) 其中: (48) 其中: (49)已知:A= ,B=