Question 111740
Use elimination to solve: 

{{{x/3}}} + 4y = 30
2x - y = 5
:
The first thing we want to do, is get rid of the denominator in the 1st equaton
Multiply equation by 3 and you have:
:
x + 3(4y) = 3(30)
x + 12y = 90
:
So now are two equations are:
x + 12y = 90
2x - y = 5
:
In order to eliminate x, we multiply the 1st equation by 2 and subtract the 2nd eq:
2x + 24y = 180
2x -  y = 5
--------------subtracting eliminates x, find y
0x + 25y = 175
y = {{{175/25}}}
y = 7
:
Find x using the 1st equation, substitute 7 for y
x + 12(7) = 90
x + 84 = 90
x = 90 - 84
x = 6
:
Check our solutions using the 2nd equation: substitute for x and y
2(6) - 7 = 5; we can see that equality reigns, so our solutions are correct
:
Did this help you understand this a little better?