We only want x terms on the left,
cx + 4c = 5x + 7c so get the x term off the right
-5x -5x by adding -5x to both sides.
------------------------
-5x + cx + 4c = 7c 4c does not contain x, so
- 4c - 4c get if off the left side by
------------------------ adding -4c to both sides.
-5x + cx = 3c
Factor out x on the left
x(-5 + c) = 3c
Get rid of the multiplied -5+c
by dividing both sides by it
x(-5 + c) 3c
覧覧覧覧覧 = 覧覧覧覧覧
-5 + c -5 + c
Cancel the -5+c on the left:
3c
x = 覧覧覧覧覧
-5 + c
That's the answer, but maybe your teacher would think it would look better
if you wrote the denominator like this:
3c
x = 覧覧覧覧覧
c - 5
Edwin