The sum of two numbers is 10. if one number is subtracted from the other the result is - 2. find two numbers

Form an equation to describe the situation

x+y=10

Then use the other information they gave you and form another equation

x-y=2

You can add the two equations together, and you see that the y variables cancel out (elimination)

2x=12

Solve for one variable and then plug it back into the original equation

x=6

6+y=10

y=4