I'm going to assume that you are trying to find the two numbers. Based on the information in the problem, we can create the following equations (where [tex]a[/tex] and [tex]b[/tex] are the two numbers):
[tex]a + b = 30[/tex]
[tex]a - b = 6[/tex]
We have a systems of equations. In this case, it would be easier to use elimination by adding vertically. This produces the result:
[tex]2a = 36[/tex]
[tex]a = 18[/tex]
To find [tex]b[/tex], substitute the value for [tex]a[/tex] into one of the earlier equations:
[tex]18 + b = 30[/tex]
[tex]b = 12[/tex]
The two numbers are 12 and 18.
