Simultaneous equations using elimination method?

x - 4y = -4 (1)
4x - 2y = 12 (2)
4 x (1) gives 4x -16y = -16 (3)
(2) -(3) gives 14y = 28
y = 28/14 = 2
substitute y = 2 into (1)
x -4(2) = -4
x - 8= -4
x = -4 +8 = 4
>>>> (4,2)
 
To find y-Before doing anything else, multiply the first equation by 4. So you have 4x - 16y = -16
Then you subtract the second equation from it. (4x - 16y) - (4x - 2y) = -16 - 12
solve it. 4x - 4x cancels out. -16y - -2y = -14y. -16 - 12 = -28
so you have -14y = -28
divide each side by 14. y = 2.

Then substitute 2 for x in one of the equations (whichever you choose) and solve it from there. :)
 
x - 4y = -4
4x - 2y = 12

double bottom equation

8x - 4y = 24
x - 4y = -4

subtract both

7x = 28

x = 28/7
x=4

substitute x=4 into equation 1
4 - 4y = -4
-4y = -4-4
-4y = -8
y = -8/-4
y = 2

So x = 4 and y = 2
 
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