7(a-1)+x(a-1),3(a-b)²+6(b-a),2(m-n)²-m(m-n),x(x-y)²-y(y-x)²,
问题描述:
7(a-1)+x(a-1),3(a-b)²+6(b-a),2(m-n)²-m(m-n),x(x-y)²-y(y-x)²,
不想光要答案m(a²+b²)+n(a²+b²)
答
7(a-1)+x(a-1)=(7+x)(a-1)3(a-b)²+6(a-b)=(a-b)(3(a-b)+6)=(a-b)(3a-3b+6)2(m-n)²-m(m-n)=(m-n)(2(m-n)-m)=(m-n)(2m-2n-m)=(m-n)(m-2n)x(x-y)²-y(y-x)²=x(x-y)²-y(x-y)²=(x-y)²(...内个我还有几道需要解答一下18(a-b)³-12b(b-a)²,(2a+b)(2a-3B)-3a(2a+b)谢谢