Sometimes you have a formula and you need to solve for some variable other than the "standard" one. Example: Perimeter of a square

P=4sIt may be that you need to solve this equation for s, so you can plug in a perimeter and figure out the side length.

This process of solving a formula for a given variable is called "solving literal equations".

Here's how "solving literal equations" works:

Suppose you wanted to take the formula for the perimeter of a square and solve it for ‘s’ (or the side length) instead of using it to solve for perimeter.

P=4sHow can you get the ‘s’ on a side by itself?

P=4s

Just as when you were solving linear equations, you want to isolate the variable. So, what do you have to do to get rid of the ‘4’?

That’s right, you have to divide by ‘4’. You also have to remember to divide both sides by 4.

P=4s

This new formula allows us to use the perimeter formula to find the length of the sides of a square if we know the perimeter.

      

Multiply both sides by 2.

Subtract ‘c’ from each side.

As you can see, we sometimes must do more that one step in order to isolate the targeted variable.

You just need to follow the same steps that you would use to solve any other ‘Multi-Step Equation’.

Work these on your paper.

Solve for Solve for t.t.

Check your answers.