因式分解：已知,a+b=2,ab=2,求2分之一a^3b+a^2b^2+二分之一ab^3的值 马上要!还有一道：已知x+y=5,xy=4,求：x^2y+xy^2
网友回答
(1)原式=1/2ab(a^2+2ab+b^2)
=1/2ab(a+b)^2
=1/2×2×2^2
=4(2)x^2y+xy^2
=xy(x+y)
=5×4=20======以下答案可供参考======
供参考答案1:
原式=1/2ab(a^2+2ab+b^2)
=1/2ab(a+b)^2
=1/2×2×2^2
=4供参考答案2:
(1)原式=1/2ab(a^2+2ab+b^2)
=1/2ab(a+b)^2
=1/2×2×2^2
=4(2)x^2y+xy^2
=xy(x+y)
=5×4=20