Question

1.若a+b=1/2,ab=3/8,求多项式a³b+2a²b²+ab³的值?

Answer 1

1,a3b+2a2b2+ab3=ab(a2+b2+2ab)=ab(a+b)^2=3/8 *1/4=3/32

2,x=3,y=-2,xy=-6

3,等边三角形.a2+b2+c2=ab+ac+bc可以化简：(a-b)^2+(a-c)^2+(b-c)^2=0,所以a=b=c