How do you solve #9=7z-13z-21#?
When solving equations, we can combine like terms as shown below:
So to solve this problem, we need to isolate the variable "
We do this by combining all terms with the variable
Then we treat it as a regular algebra problem by isolating the variable
Note: Combining like terms can only be done with variables of the same degree, or in other words, variables raised to the same exponent. Example below: