" (iv) "x+y=xy^(3)

Let a function of 2 variables be defined by g(x, y)=xy+3xy^(2)-(x-y^(2)) , what is the value of g(2, -1) ?

If x,y in R and x^(2)+y^(2)+xy=1, then find the minimum value of x^(3)y+xy^(3)+4

What does the equation x^(3)y+xy^(3)-xy=0 represent?

for x=3 and y=-2 verify that (x-y)^(3)=x^(3)-y^(3)-3xy(x-y)

x^(3) + x^(2)y+ xy^(2) + y^(3) = 81