Question

Pl ease H e l p I'm literally desperate-

If f(x) = 4x - 5 and g(x) = 7x -3, Show all steps & work. Find:
(f + g) (x)
and
(f * g) (x)

Answer 1

Answer:

f+g = 11x-8

f*g = 28x^2 - 47x+15

Step-by-step explanation:

f(x) = 4x - 5 and g(x) = 7x -3

(f+g)(x) = 4x - 5  + 7x -3

Combine like terms

         = 4x+7x -5-3

        = 11x-8

(f * g) (x) = ( 4x - 5) (7x -3)

FOIL

          = 4x*7x + 4x(-3) + (-5)(7x) + (-5)(-3)

            =28x^2 -12x-35x+15

Combine like terms

            =28x^2 - 47x+15

Answer 2

Step-by-step explanation:

Step 1:  Find (f + g)(x)

The definition of (f + g)(x) is f(x) + g(x).  Basically add the two functions together.  

$f(x) + g(x)$

$(4x - 5) + (7x - 3)$

$11x - 8$

Answer:  $11x - 8$

Step 2:  Find (f * g)(x)

The definition of (f * g)(x) is f(x) * g(x).  Basically multiply the two functions together.  

$f(x) * g(x)$

$(4x - 5) * (7x - 3)$

$(4x * 7x) + (4x * -3) + (-5 * 7x) + (-5 * -3)$

$(28x^{2}) + (-12x) + (-35x) + (15)$

$28x^{2} - 47x + 15$

Answer:  $28x^{2} - 47x + 15$