I'm going to rewrite f(x) and g(x) so that I don't get confused.
Based on your description:
f(x) = (2x)
+ x - 1 simplified to 4x + x - 1
g(x) = x + 3x - 3
Now we handle parts A-D.
A. f(x) + g(x)
We combine like terms.
4x + 5x + x + 3x - 1 - 3 = 5x + 4x - 4
B. f(x) - g(x)
Again combine like terms like normal except this time subtracting.
4x - x + x - 3x - 1 - (- 3) = 3x - 2x + 2
C. 2f(x) + 2g(x)
Multiply, then again CLT
2f(x) = 8x + 2x - 2
2g(x) = 2x + 6x - 6
Combine like terms to get 10x + 8x - 8
D. 2f(x) - 2g(x)
Use the same 2f(x) and 2g(x) terms and this time just subtract.
You get 6x - 4x + 4
Based on your description:
f(x) = (2x)
g(x) = x
Now we handle parts A-D.
A. f(x) + g(x)
We combine like terms.
4x
B. f(x) - g(x)
Again combine like terms like normal except this time subtracting.
4x
C. 2f(x) + 2g(x)
Multiply, then again CLT
2f(x) = 8x
2g(x) = 2x
Combine like terms to get 10x
D. 2f(x) - 2g(x)
Use the same 2f(x) and 2g(x) terms and this time just subtract.
You get 6x