7x - 3x = 24
The 7x and the 3x are both like terms, so they can be combined. 7 - 3 is 4, so the equation turns into
4x = 24
Now, you want to get the x alone, so you divide both sides by 4 because it is the opposite of multiplication. 24 divided by 4 is 6, so
x = 6
