This is a great pre-algebra questions! (Don't worry. It's easier than it looks.)
We just have to remember two things:
1) Our goal is to get "x" all by itself on the left side of the equal sign.
2) Whatever we do to one side of the equation, we must also do to the other side of the equation.
Let's take a closer look: 15x + 6 = 36.
We're trying to get x all alone on the left side, so that 6 will definitely have to go! To get rid of something we don't want, we subtract it. Let's subtract 6 from both sides of the equation.
15x + 6 - 6 = 36 - 6.
On the left side of the equation, 6 minus 6 = 0. That leaves us with 15x + 0, but we don't need to actually write "+ 0", since adding 0 to something doesn't change its value. Instead, we can now write just plain old "15x" on the left side of the equation. On the right side, we subtracted 6 from 36, so now we have:
15x = 30
We're halfway there! We know that 15x = 30. Of course we don't want 15 of x; we only want one x. (Remember, when we see a variable such as "x" or "y," that always means 1x or 1y. The one is understood, so it's not written beside the variable.)
To find the value x, we'll need to divide 15x (which is a shorter way of saying "15 times x") by 15, and, of course, we'll have do the same thing to the right side of our equation.
15x ÷ 15 = 30 ÷ 15
This means that x has to be equal to 30 ÷ 15, so.....
x = 2.
See? That wasn't so bad. :-)
