3ab (4a*2-b*2)+4ab (b*2-3a*2) при a=10,b=-5

Question

3ab (4a*2-b*2)+4ab (b*2-3a*2) при a=10,b=-5

Answer 1

3ab(4a*2-b*2)+4ab(b*2-3a*2)=3ab(8a-2b)+4ab(2b-6a)=24a²b-6ab²+8ab²-
24a²b=-6ab²+8ab²=2ab²=2*10*(-5)²=20*25=500