Answer
$I : \frac{c}{(a + b)}$
Work Step by Step
The origional equation is ax + bx = c.
In order to solve for x, we can simplify it into x (a + b) = c
To get x on one side, we need to divide (a+b) from both sides
So, now we get x = $\frac{c}{(a + b)}$
The answer choice is $I$.
