已知(a+2)²+(3b-1)²=0,
a+2=0,3b-1=0
a=-2,b=1/3
所以
3a²b-2[2ab²-6(ab-a²b)+4ab]-2ab
=3a²b-4ab²+12ab-12a²b-8ab-2ab
=-9a²b-4ab²+2ab
=ab(-9a-4b+2)
=-2×1/3×(-9×(-2)-4×1/3+2)
=-2/3×(18-4/3+2)
=-2/3×56/3
=-112/9
已知(a+2)²+(3b-1)²=0,
a+2=0,3b-1=0
a=-2,b=1/3
所以
3a²b-2[2ab²-6(ab-a²b)+4ab]-2ab
=3a²b-4ab²+12ab-12a²b-8ab-2ab
=-9a²b-4ab²+2ab
=ab(-9a-4b+2)
=-2×1/3×(-9×(-2)-4×1/3+2)
=-2/3×(18-4/3+2)
=-2/3×56/3
=-112/9