Question

1/2a³b+a²b²+1/2ab³因式分解

解答一道因式分解题
若a(a-1)-(a²-b)=-2,求a²+b²/2-ab的值
已知a+b=2 ab=1 求1/2a³b+a²b²+1/2ab³的值

Answer 1

1,a(a-1)-(a²-b)=-2
a^2-a-a^2+b=-2
a-b=2
(a-b)^2=4
a^2+b^2=4+2ab
a²+b²/2-ab=2+ab-ab=2
2,1/2a³b+a²b²+1/2ab³
=1/2ab(a^2+2ab+b^2)
=1/2*4
=2