Question

How do you solve `2x = 4` and `2x – y = 5`?

Answer 1

`{(x = 2), (y = -1) :}`

Explanation:

Notice that you can find the value of `x` from the first equation by dividing both sides by `2`

`(color(red)(cancel(color(black)(2))) * x)/color(red)(cancel(color(black)(2))) = 4/2`

`x = color(green)(2)`

Now simply take this value of `x` and plug it into the second equation. This will allow you to find the value of `y`

`2x - y = 5`

`2 * (2) - y = 5`

`4 - y = 5`

This is equivalent to

`y = 4 -5 = color(green)(-1)`