Find an equation of the line. Write the equation using function notation.
-$( 3 , - 19 ) , ( 6 , - 40 )$
A) $f ( x ) = 7 x - 40$
B) $f ( x ) = - 7 x + 2$
C) $y = - 7 x + 2$
D) $y = - \frac { 1 } { 7 } x - \frac { 130 } { 7 }$

Question

Quizplus · Accepted Answer

First, find the slope (m) using the formula $m = \frac{y_2 - y_1}{x_2 - x_1}$, which gives $m = \frac{-40 - (-19)}{6 - 3} = \frac{-21}{3} = -7$. Then, use point-slope form $y - y_1 = m(x - x_1)$ with one of the points, say $(3, -19)$, to get $y + 19 = -7(x - 3)$. Simplify to get $y = -7x + 21 - 19$, which is $y = -7x + 2$. Since we need function notation, $f(x) = -7x + 2$ is correct.

Find an Equation of the Line (3,−19),(6,−40)( 3 , - 19 ) , ( 6 , - 40 )(3,−19),(6,−40)

Find an Equation of the Line $( 3 , - 19 ) , ( 6 , - 40 )$