Question

If (2, -20) and (-3, 35) are two anchor points on a trend line, then find the equation of the line.

Answer 1

y = - 11x + 2

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, - 20 ) and (x₂, y₂ ) = (- 3, 35 )

substitute these values into the formula for m

m =
`(35-(-20))/(-3-2)` =
`(35+20)/(-5)` =
`(55)/(-5)` = - 11 , then

y = - 11x + c ← is the partial equation

to find c, substitute either of the 2 points into the partial equation

using (2, - 20 ) for x and y in the partial equation

- 20 = - 11(2) + c = - 22 + c ( add 22 to both sides )

2 = c

y = - 11x + 2 ← equation of line