Isolating a Variable
Often math problems ask you to “Find x.” As simple as it sounds, that can be a very complex and precise process. Follow these steps to isolate variables in mathematical equations. Some steps will not be required, but it is important to go in order and check each step to avoid errors. Remember to always pay careful attention to negative signs!
1) Combine like terms inside parentheses
2) Distribute across the parentheses
– Multiply everything inside the parentheses by the coefficient in front
3) Combine like terms on the same side of the equal sign
– Combine all constants by adding
– Combine all like variable terms by adding the coefficients
4) Add/Subtract (do the “opposite operation”) the constant on one side of the equal sign, and do the same to the other side
5) Add/Subtract (do the “opposite operation”) the variable term from one side to get it on the other side of the equal sign, away from the constant.
6) Divide both sides by the coefficient
Check out this example, noting the numbers 1-6 to the right indicating which step is taking place.