For the substitution I have no idea what to do because for the example you did for me it only had one variable on the top line at the right, then an equation on the right. The other one is two variables on the left and a number on the right.

For the elimination:

-7s=27

s=-27/7

and I get3.857142857, and I know that's not right. I was trying to follow your example.

And now I have to sleep. Hopefully I can get it in the morning.=> - 5q = 15 ...................(2) - (1)

=> q = -15/5 = -3

But 4p + 2q = 10

so 4p + 2(-3) = 10

=> 4p - 6 = 10

=> 4p = 10 + 6 = 16

=> p = 16/4

=> p = 4

So p = 4, q = -3