a+b=2,ab=3求代数式2a^3b+2ab^3的值

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a+b=2,ab=3求代数式2a^3b+2ab^3的值
a+b=2,ab=3求代数式2a^3b+2ab^3的值

a+b=2,ab=3求代数式2a^3b+2ab^3的值
2a³b+2ab³
=2ab(a²+b²)
=2ab[(a+b)²-2ab]
=2×3×[2²-2×3]
=6×(-2)
=-12

2a^3b+2ab^3
=2ab(a^2+b^2)
=2ab[a^2+b^2+2ab-2ab]
=2ab[(a+b)^2-2ab]
=2*3*[2^2-2*3]
=-12

2a^3b+2ab^3
=2ab(a^2+b^2)
=2ab[(a+b)^2-2ab]
=2*3*[2^2-2*3]
=2*3*(-2)
=-12

2a^3b+2ab^3=2ab(a^2+b^2)=2ab[(a+b)^2-2ab]=2*3*(2^2-2*3)=-12