The perimeter of a triangle is and the length of two of its sides are and . Find the length of the third side in terms of .
Step 1: Find the sum of the lengths of the two given sides.
Use the commutative and associative properties to change the order of the terms and group like terms together. Then combine like terms.
Step 2: To find the length of the third side, subtract the sum of the two given sides from the perimeter.
Group together and combine like terms as you did in the previous step.