Answer:
[tex]Sum = 5x[/tex]
Step-by-step explanation:
Given
1: 5x + 20
2: Opposite of 20
Required
Find their sum
Suppose that a is a number; The opposite of a is -a. So, the opposite of 20 is -20.
Having said that:
The required sum is:
[tex]Sum = 5x + 20 + (-20)[/tex]
Remove bracket
[tex]Sum = 5x + 20 -20[/tex]
[tex]Sum = 5x[/tex]