Solve for x: 2x+5=21

*Notice that ***2 is "closest"** to variable x, and** 5 is "farthest"** away. This simple observation allows us to decide which number to eliminate first. It is obviously +5 because it is farther between the two. The opposite of +5 is -5, so that means we will subtract both sides of the equation by 5.

*2x+5-5=21-5*

2x=16

Now it's time to get rid of the number closest or directly attached to x which is 2. Since +2 is multiplying the variable x, its opposite operation is to divide by 2.