Question

HELP I GOT THE WRONG ANSWER
Medal+Fan

If f(x) = 3x + 5 and g(x) = 2x - 9, find f(x) + g(x).

A. 5x + 4
B. x - 4
C. x + 14
D. 5x - 4

I choose C as the answer but i got it wrong

Answer 1

Make sure you keep the (2x-9) in brackets

Answer 2

so you have 5-9, not 5+9

Answer 3

You might want to re-arrange your two functions into columns, as shown:

f(x) = 3x + 5
+ g(x) = 2x - 9
----------------

Simply add up each of the 3 columns shown.

Write your answer as f(x)+g(x) = ?x + ?

Answer 4

f(x) = 3x + 5=x
+ g(x) = 2x - 9=4.5

@mathmale

Answer 5

Simply add up each of the 3 columns shown.

f(x) = 3x + 5
+ g(x) = 2x - 9
----------------
f(x)+g(x) = 5x - 4

Note that we're NOT trying to solve for x, so x=4.5 is not what is called for.

We're just combining the two linear functions to obtain

f(x)+g(x) = 5x - 4.

Answer 6

@Ambbiiee : Are you OK with the solution of this problem, or would you like more discussion of it?