y分之xy²-x³÷(x-y)² × (x+y)分之(x-y),其中x=1.5,y=2

问题描述:

y分之xy²-x³÷(x-y)² × (x+y)分之(x-y),其中x=1.5,y=2

∵x=1.5=3/2,y=2
∴x+y=7/2,x-y=-1/2,xy=3
∴[(xy^2)/y]-[x^3/(x-y)^2][(x+y)/(x-y]=3-[(3/2)^3/(-1/2)^2][(7/2)/(-1/2)]=3-(27/2)(-7)=195/2