Question 246893
you aren't trying to eliminate numbers but letters.
for example
with the linear equations (they make a line on if you graph it)
x-y=7
2x+y=8
if you add the two equations y will be gone because we have a minus y and a plus y

with the equations 
8x+y=23
3x+y=10
if we subtract one from the other we eliminate the y's because y-y =0
so you need to multiply your equations by a number such that you can subtract or add then and get rid of one of the letters
try multiplying the first one by 2 and the second one by 3
that way you'll have 6x in both and can subtract them.
then you solve for y
and then when you have y can plug y into any of the equations and solve for x
Me being a wise guy :-)
Did you miss class the day that was explained?