Question

How do you find the slope-intercept of `y = - 4x`?

Answer 1

slope `=-4`
y-intercept `=0`
(x-intercept `=0`)

Explanation:

The general slope-intercept form is
`color(white)("XXX")y=color(green)(m)x+color(blue)(b)`
with a slope of `color(green)(m)` and a y-intercept of `color(blue)(b)`

`y=-4x` is equivalent to `y=(color(green)(-4))x+color(blue)(0)`
which is the slope-intercept form
with slope `(color(green)(-4))`
and y-intercept `color(blue)(0)`

To determine the x-intercept, note that the x-intercept is the value of `x` when `y=0`
`color(white)("XXX")y=-4x` evaluated with `y=0`
`color(white)("XXX")`implies `x=0`