If the value for only one of the variables is given
Look over the problem below.
b = 3
As you can see, the expression has two variables b and c, but in this problem, only the value for b is given. Don't panic! Simply substitute the variable b with the number 3, don't worry about doing anything with the variable c.
5(3) - 2c + c / (3)
Then simplify as much as you can using the Order of Operations:
If the value for one of the variables is not a number
In this case, as in the problem below, you must substitute the variable with the expression given.
b = c + 1
NOTEThis problem is one instance where it is absolutely necessary to enclose the expression or number that you are substituting a variable for in parentheses. Because of the Order of Operations 5(c + 1) is not the same as 5c + 1.
5(c + 1) - 2c + c / (c + 1)
5c + 5 - 2c + c / (c + 1)
Proceed to the next page for more substitution resources.