化简求值：5(3a²b-ab²)-(ab²+3a²b),其实a=2分之1,b=-1

化简求值：5(3a²b-ab²)-(ab²+3a²b),其实a=2分之1,b=-1
化简求值：5(3a²b-ab²)-(ab²+3a²b),其实a=2分之1,b=-1

化简求值：5(3a²b-ab²)-(ab²+3a²b),其实a=2分之1,b=-1
解
原式
=(15a²b-3a²b)+(-5ab²-ab²)
=12a²b-6ab²
=6ab(2a-b)
=6×1/2×(-1)(2×1/2+1)
=-3×2
=-6