If f (x) = 7x - 3 and g (x) = x2 - 4x - 8, find (f + g) (x).

The value of (f+g) (x) is x^2 + 3x - 11

You can combine this by simply adding the like terms. Start by adding together all of the x^2 terms. Since only g (x) has one of those, we use that in its entirety.

x^2

Next we add together the x terms. f (x) has 7x and g (x) has - 4x.

7x + - 4x = 3x

Finally, we add together the constants. f (x) has - 3 and g (x) has - 8.

-3 + - 8 = - 11

With all of the like terms combined, we simply take the answers and put them together.

x^2 + 3x - 11