Question

How do you solve the system of linear equations `4x + y = 8` and `x − 2y = 2`?

Answer 1

`(x,y)=(2,0)`

Explanation:

Given
[1]`color(white)("XXX")4x+y=8`
[2]`color(white)("XXX")x-2y=2`

From [2], we have
[3]`color(white)("XXX")x=2+2y`

Substituting `(2+2y)` of `x` in [1]
[4]`color(white)("XXX")4(2+2y)+y=8`

[5]`color(white)("XXX")8+3y=8`

[6]`color(white)("XXX")y=0`

Substituting `0` for `y` in [2]
[7]`color(white)("XXX")x-(2 * 0)=2`

[8]`color(white)("XXX")x=2`