Question

Answer 1

\(xy=\dfrac{\left(x+y\right)^2-\left(x^2+y^2\right)}{2}=\dfrac{4-10}{2}=-3\)

\(\Rightarrow x^3+y^3=\left(x+y\right)^3-3xy\left(x+y\right)=2^3-3.\left(-3\right).2=26\)

Answer 2

`x + y = 2 -> x^2 + 2xy + y^2 = 4 -> 2xy = 6 -> xy = 3.`

`-> x^3 + y^3 = (x+y)(x^2 - xy + y^2)  = 2 . (10 - 3) = 14`