Solve using the quadratic formula a^2 +2a-8=0

For how answer my question this will be the last question can you answer in math subject

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

Multiply and simplify. 2x^2 y^3 z^2 · 4xy^4 x^2 i will mark you brainliest if right. show how you got the answer, !