How do solve the following linear system?: x-4y=2 , x-7y=4 x4y=2,x7y=4?

1 Answer
Dec 28, 2015

(-2/3,-2/3)(23,23)

Explanation:

Try to leave xx alone in one side of the equation, then equate the other sides;

x=2+4y , x=4+7yx=2+4y,x=4+7y

2+4y=4+7y2+4y=4+7y -> -3y=23y=2
y=-2/3y=23

Now, write -2/323 instead of yy in one of the equations, the value of xx will be the same for both of them.

x=2+4.(-2/3)x=2+4.(23) -> x=2-8/3x=283
x=-2/3x=23