Question

化简求值x^2+xy+y^2/x^2+xy乘x,其中x=2,y=-1

Answer 1

1、=（a-2）^2/(a+1)^2乘（a+1）/(a+2)(a-2)=(a-2)/(a+1)(a+2)=a^2+3a+2

2、=（y-3）/4(y-2)乘（y-2）/(y+3)(y-3)=1/4(y+3)=1/(4y+12)