Question

A line with a slope of -9 passes through the points (s, 8) and (-8, -10). What is the value of

s?
S=

Answer 1

s = - 10

Explanation:

calculate the slope m using the slope formula and equate to - 9

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

let (x₁, y₁ ) = (s, 8 ) and (x₂, y₂ ) = (- 8, - 10 )

substitute these values into the formula for m

m =
`(-10-8)/(-8-s)` =
`(-18)/(-8-s)`

Now equate this expression for m to - 9

`(-18)/(-8-s)` = - 9 ( multiply both sides by (- 8 - s )

- 18 = - 9(- 8 - s) ← divide both sides by - 9

2 = - 8 - s ( add 8 to both sides )

10 = - s ( multiply both sides by - 1 )

- 10 = s