Question

Write the equation of the line in fully simplified slope-intercept form.

Answer 1

y = - x - 1

Explanation:

the equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

calculate the slope m, using the slope formula

m =
`(y_(2)-y_(1) )/(x_(2)-x_(1) )`

let (x₁, y₁ ) = (- 2, 1) and (x₂, y₂ ) = (1, - 2) ← 2 points on the line

substitute these values into the formula for m

m =
`(-2-1)/(1-(-2))` =
`(-3)/(1+2)` =
`(-3)/(3)` = - 1

the line crosses the y- axis at (0, - 1 ) , then c = - 1

y = - x - 1 ← equation of line