How do you solve 2x - y = 4 and 4x = 2y + 8?

1 Answer
Don't Memorise
Apr 7, 2015

Dividing both sides of the second equation by 2, we get

(4x)/2 = (2y)/2+8/2

2x = y + 4

2x-y = 4

This is the same equation as the first one. It means that there are INFINITE solutions for x and y.
Any values of x and y that satisfy the first equation will also satisfy the second one.

For eg. if we choose x = 2, y = 0:

First equation :
2x-y = 4
(2*2) - 0 = 4 (which is equal to the Right Hand Side)

Second equation :
4x = 2y + 8
Left Hand Side is 4x = 4*2 = 8
And the Right Hand Side is 2y + 8 = (2*0) + 8 = 8

Both the equations will be satisfied for various such values of x and y like (3,2); (4,6) and so on..

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