问题
解答题
计算: (1)(-3)0+(-
(2)(2x-3y)2-(3x+y)(3x-y) (3)(x+y)(x2+y2)(x-y) (4)(m-n-3)2 |
答案
(1)原式=1+4÷2=1+2=3;
(2)原式=4x2-12xy+9y2-(9y2-y2)=4x2-12xy+9y2-9y2+y2=-5x2-12xy+10y2;
(3)原式=(x2-y2)(x2+y2)=x4-y4;
(4)原式=[(m-n)-3]2=(m-n)2-6(m-n)+9=m2-2mn+n2-6m+6n+9.