Question

How do you find the slope and intercept of `x+y=9`?

Answer 1

`"slope "=-1" and y-intercept "=9`

Explanation:

The equation of a line in `color(blue)"slope-intercept form"` is

`color(red)(bar(ul(|color(white)(2/2)color(black)(y=mx+b)color(white)(2/2)|)))`
where m represents the slope and b, the y-intercept.

`"Rearrange " x+y=9" into this form"`

subtract x from both sides of the equation.

`cancel(x)cancel(-x)+y=9-x`

`rArry=-x+9larrcolor(red)" in slope-intercept form"`

`rArr"slope "=m=-1" and y-intercept "=b=9`