Question

How do you find the x- and y-intercept of the line 4x – 7y = 84?

Answer 1

See the entire solution process below:

Explanation:

y-intercept: Substitute `0` for `x` and solve for `y`:

`4x - 7y = 84` becomes:

`(4 * 0) - 7y = 84`

`0 - 7y = 84`

`-7y = 84`

`(-7y)/color(red)(-7) = 84/color(red)(-7)`

`(color(red)(cancel(color(black)(-7)))y)/cancel(color(red)(-7)) = -12`

`y = -12`

The y-intercept is `-12` or `(0, -12)`

x-intercept: Substitute `0` for `y` and solve for `x`:

`4x - 7y = 84` becomes:

`4x - (7 * 0) = 84`

`4x - 0 = 84`

`4x = 84`

`(4x)/color(red)(4) = 84/color(red)(4)`

`(color(red)(cancel(color(black)(4)))x)/cancel(color(red)(4)) = 21`

`x = 21`

The x-intercept is `21` or `(21, 0)`