Question

x=2,y=-2分之一,则x的立方乘y的立方加3乘x的平方乘y的平方加2分之一乘x乘y得几

Answer 1

x³y³+3x²y²+xy/2

=(xy)³+3(xy)²+xy/2

∵x=2,y=-1/2

∴xy=-1

∴原式=(-1)³+3*(-1)²-1/2

=-1+3-1/2

=3/2