Question

If f(x) = x^2 - 2x and g(x) = 6x + 4, for which value of x does (f + g)(x) = 0

Answer 1

So for this, we will be adding f(x) and g(x) together and setting (f + g)(x) to 0 as such:

`x^2-2x+6x+4=0`

Firstly, combine like terms:

`x^2+4x+4=0`

Next, the left side of the equation is a perfect square. Factor it:

`(x+2)^2=0`

Next, square root both sides:

`x+2=0`

Lastly, subtract 2 on both sides and your answer will be
`x=-2`

Answer 2

(f + g)(x) = 0

x^2 - 2x + 6x + 4 = 0

x^2 + 4x + 4 = 0

(x + 2)^2 = 0

x + 2 = 0

x = -2