Assume f (x) = - 2+8 and g (x) = 3x what is the value of (f+g) (-1)

The meaning of (f + g) (-1) is you substitute - 1 to x of whatever polynomial you obtain after adding the polynomials f (x) and g (x).

f (x) + g (x) = - 2x + 8 + 3x = x + 8

Substitute - 1,

(f + g) (-1) = - 1 + 8 = 7.

Thus, the answer is 7.