求值a^4+3ab-6a^2b^2-3ab^2+4ab+6a^2b-7a^2b-2a^4+b^4其中=-2,b=-1
问题描述：
求值a^4+3ab-6a^2b^2-3ab^2+4ab+6a^2b-7a^2b-2a^4+b^4其中=-2,b=-1
答
a^4+3ab-6a^2b^2-3ab^2+4ab+6a^2b-7a^2b-2a^4+b^4=-a^4+7ab-6a^2b^2-3ab^2-a^2b+b^4先把b=-1代入=-a^4-7a-6a^2-3a+a^2+1=-a^4-10a-5a^2+1=-(-2)^4-10*(-2)-5*(-2)^2+1=16+20-20+1=17