知能提升小专题(六 整式的加减运算专练 类型1整式的化简 1.化简 (1)3(2x2y-3xy2)-2(2xy2-3x2y); 解:原式=6x2y-9xy2-4xy2+6x2y =12x2y-13xy2
(2)(-m23-6m)+5m2-(-m3-2m2+3m); 解:原式=-m3-6m+5m2+m3+2m2-3m =7m2-9m (3)(x2+2x+1)-(2x-3-4x2); 解:原式=x2+2x+1-2x+3+4x2 5x2+4
(4)3a-[-2b+2(a-3b)-4a]; 解:原式=3a+2b-2a+6b+4a =5a+8b (5)8a2-[5a-8a2-(2a2-3a)+9a2]; 解:原式=8a2-(5a-8a2-2a2+3a+9a2) 89 a2-8a+a 2-8a
(6)(3a-2a2)-[5a-(6a2-9a)-4a2 解:原式=3a-2a2-5a+2a2-3a+4a2 =4a2-5a 2.已知A=2x2-9x-11,B=3x2-6x+4.求: (1)A-B; (2)A+2B. 2 解:(1)A-B=(2x2-9x-11)-(3x2-6x+4) =2x2-9x-11-3x2+6x-4 =-x2-3x-15
(2)nA+2B=2 (2x2-9x-11)+2(3x2-6x+4) 911 x-2x-2+6x-12x+8 7 2×5 33 2