How do you solve x-2y=4 and -x+6y=12?

1 Answer
Dec 1, 2015

color(green)(x = 12
color(green)(y = 4

Explanation:

x-2y=4 -----(1)
-x+6y=12 ------(2)

The question is asking us the find the values of x and y which satisfy both these equations

To find the value of x, we just need to eliminate y

We can do that by adding the two equations. We get:

(x - 2y) + (-x + 6y) = 4+12

->cancel(x) - 2y - cancel(x) + 6y = 16

4y = 16

color(green)(y = 4

To get the value of x, we can easily substitute this value of y in any of the two equations

Substituting it in the first equation, we get

x - 2(4) = 4

->x - 8 = 4

Transposing 8 to the other side, we get

-> x = 4 + 8

color(green)(x = 12