## Video: How to Solve for the Value of an Expression (Without Solving for its Variables!)

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As Jess and Rich explain in this GMAT video, oftentimes on Data Sufficiency problems you’ll be given more variables than you have equations. This happens for two main reasons:

- You’re just given more variables than equations (you know, because it’s fun)
- You’re given as many variables as equations, but not all the equations are
*independent*

In these cases, you won’t be able to solve for the value of every variable in the system. But — don’t be fooled! This doesn’t necessarily mean that E is the right answer. Sometimes, you may be able to solve for the value of an expression involving multiple variables — without actually knowing the value of those variables. Confused yet? Check out the video for a sample problem and a super helpful explanation!

Want more DS help? Check out more installments of this quantitative strategy lesson!