**If x + y = 4, then find the value of x**^{3} + y^{3} + 12xy – 64.

^{3}+ y

^{3}+ 12xy – 64.

**Answer :**

It is given that

x + y = 4

By cubing on both sides

(x + y)^{3} = 4^{3}

Expanding using formula

x^{3} + y^{3} + 3xy (x + y) = 64

Substituting the value of x + y

x^{3} + y^{3} + 3xy (4) = 64

So we get

x^{3} + y^{3} + 12xy – 64 = 0

Hence, the value of x^{3} + y^{3} + 12xy – 64 is 0.

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