问题
解答题
计算:
①(6m2-4mn-3n2)-(2m2-4mn+n2)
②(-3a2b3)2•4(-a3b)3;
③(x-3)2-2(x+2)(x-2);
④(2x-y+1)(2x+y-1);
⑤(a+b)2(a-b)2;
⑥因式分4a2x2+8axy+12axy2.
答案
①(6m2-4mn-3n2)-(2m2-4mn+n2)
=6m2-4mn-3n2-2m2+4mn-n2
=4m2-4n2;
②(-3a2b3)2•4(-a3b)3
=9a4b6•(-4a9b3)
=-36a13b9;
③(x-3)2-2(x+2)(x-2)
=x2-6x+9-2(x2-4)
=3x2-6x+17;
④(2x-y+1)(2x+y-1)
=(2x)2-(y-1)2
=4x2-(y2-2y+1)
=4x2-y2+2y-1;
⑤(a+b)2(a-b)2
=(a2-b2)2
=a4-2a2b2+b4;
⑥4a2x2+8axy+12axy2=4ax(ax+2y+3y2).