solve the equation

Original question: 6x + 13 = 4x + 21

Step 1: Subtract 21 from both sides: 6x -21 + 13 = 4x +21 - 21

Result 1: 6x - 8 = 4x

Step 2: Subtract 6x from both sides: 6x - 6x - 8 = 4x - 6x

Result 2: -8= -2x

Step 3: Divide both sides by -2: -8/-2 = -2x/-2

Result 3: Remember that a negative number divided by a negative number = a positive, so...

4=x

## Comments

Isn't 8/2 = 4 instead of 2?