Can you please help me on my math review?

Given:

f(x) = 3x² + 1

g(x) = x + 4

Find

(f + g)(x) =

= f(x) + g(x)

= (3x² + 1) + (x + 4)

= 3x² + x + 5

(f - g)(x) =

= f(x) - g(x)

= (3x² + 1) - (x + 4)

= 3x² - x - 3

Domain is what value of x can exist in your function. In other word, is there any gaps in your functions where you function does not exist?

For (f + g)(x) = 3x² + x + 5

  The domain is All Real Numbers since there is no x-value in that function where your function will be undefined.

For (f - g)(x) = 3x² - x - 3

 The domain is also All Real Numbers since there is no x-value in that function where your function will be undefined.

(f + g)(x) = 3x² + x + 5

(f + g)(-5) = 3(-5)² + (-5) + 5

(f + g)(-5) = 3(25) + 0

(f + g)(-5) = 75

(f - g)(x) = 3x² - x - 3

(f - g)(-5) = 3(-5)² - (-5) - 3

(f - g)(-5) = 3(25) + 5 - 3

(f - g)(-5) = 75 + 2

(f - g)(-5) = 77

sites: