Step-by-step explanation:
For this kind of problem you use multiply the number outside of the parentheses to everything inside.
you end up with 3x-300
After this, the problem can really go two ways. A question mark isn't really use in math.
If it is a 0,
3x - 300 = 0.
Bring the 300 to the other side.
3x = 300
Divide each side by 3,
and x=100.
If the ? is more of y, you already have slope intercept form with
y = 3x - 300.
I'm not sure which you are looking for, but I hope this helped!
