Question

AlgebraName1. If f(x) = 2x - 4, find each valdea)(3)b) f(x) = 9

Answer 1

Answer:

Step-by-step explanation:

Comment

The question is since f(x) really means y, then when y = 9 what's x?

Solution

y = 2x - 4

y = 9

9 = 2x - 4                Add 4 to both sides

9+4 = 2x                 Combine

13 = 2x                    Divide both sides by 2

13/2 = 2x/2              

6.5 = x

Do you mean what is f(X) when x is 3. f(3) = 2x - 4. So what is y when x = 3

y = 2x - 4                   Substitute 3 for x

y = 2*3 - 4                  Combine

y = 6 - 4

y = 2