Orla M wrote:Hi, I'm trying out different methods to solve this. Substition is fine, but getting stuck with the elimination method on this one to solve for w, x and y:
w-2x+3y=13
2w+x-4y=-14
3w-x-2y=8
Can you please help in explaining how we do this for 3 equations?
Thanks
Subtract the first two equations from the third to eliminate every variable but y:
(3w-x-2y) - (w-2x+3y) - (2w+x-4y) = 8 - 13 - (-14)
-y = 9
y = -9.
To solve for w, plug y = -9 into the second and third equations and add the two equations:
(2w + x - 4(-9)) + (3w - x - 2(-9)) = -14 + 8
5w + 54 = -6
w = -12.
To solve for x, plug w = -12 and y = -9 into the first equation:
-12 - 2x + 3(-9) = 13
-2x - 39 = 13
x = -26.
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