Evaluate the function f(x)=x^2/3-2 when x=-6

This can be written as (x+4)(x+4)

Multiply everything in the second parenthesis by the x.

x^2 + 4x

Multiply everything in the second parenthesis by 4.

4x + 16

Add these two equations together.

x^2 + 4x + 4x + 16

Combine like terms.

x^2 + 8x + 16

Hope this helps!