Question

Hi Sir/Mam

If x + y = 4

Find the value of x^{​​​​​​3} - 64 + y^{​​​​​​3}

Pls help me solve this question

Thnx

Answer 1

x+y=4
(x+y)^3=64
x^3++3x^2 y+3xy^2+y^3=64
x^3+y^3-64= -3x^2 y -3xy^2
=-3xy(x+y)
=-3xy (4)
x^3+y^3-64 = -12xy