Question

Find the equation of the line

Answer 1

y = - x + 9

Explanation:

The equation of a line in slope- intercept form is

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

Calculate m using the slope formula

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

with (x₁, y₁ ) = (0, 9) and (x₂, y₂ ) = (9, 0) ← 2 points on the line

m =
`(0-9)/(9-0)` =
`(-9)/(9)` = - 1

The line crosses the y- axis at (0, 9 ) ⇒ c = 9

y = - x + 9 ← equation of line