8 and -8 both of their absolute values are 8
You first convert the 2 minutes and 30 seconds to 150 seconds.
Then, you take the 150s÷5m to get the number of seconds per mile.
The answer is 30s/m
So we are given a system:

Substitute x = 2 we get the system:

Multiply the first equation by -5 and the second by 2 we get the system:

Adding the two equations we get :

We find the value of y by using any of the other equations like this:

Final solution:
Any number that ends with a 0 or a 5 would be a multiple of 5 because as you multipy numbers by 5 you start to see a pattern in the ones place of 5,0,5,0,5,0,5,0,... And so on forever