Question

If `y=2x-3` what is `x` when `y=5`?

Answer 1

`color(green)(x=4)`

Explanation:

If `color(red)(y) = 2color(blue)(x)-3`
then when `color(red)(y)=color(red)(5)`
`color(white)("XX")color(red)(5)=2color(blue)(x)-3`

Adding `3` to both sides
`color(white)("XX")8=2color(blue)(x)`

Then dividing both sides by `2`
`color(white)("XX")4=color(blue)(x)`
or (equivalently)
`color(white)("XX")color(blue)(x)=4`