Question

if x+y+2=0 find x³+y³+8

Answer 1

x+y+2=0
x+y=-2
(x+y)^3=(-2)^3
x^3+y^3+3xy(x+y)=-8
x^3+y^3+3xy(-2)=-8
x^3+y^3-6xy=-8
x^3+y^3+8=6xy

Answer 2

x+y+2=0

(x)³ + (y)³ + (2)³ = 3 × x × y × 2

x³ + y³ + 8 = 6xy