### Home > CC4 > Chapter 5 > Lesson 5.1.2 > Problem5-23

5-23.
1. Calculate the slope of the line through the points (6, –8) and (3, –4). Homework Help ✎

1. Write the equation of the line.

2. Is the point (–3, 4) on the line you found in part (a)? How can you tell?

Review the Math Notes box in Lesson 2.3.2.

If you substitute −3 in for x, will the value of y be 4?

${\text{slope: }\frac{\text{rise}}{\text{run}}=\frac{-8-(-4)}{6-3}=-\frac{4}{3}}$

${\text{Substitute slope and one point into }\textit{y}=\textit{mx} + \textit{b}\text{ and evaluate for } \textit{b}: -8 =-\frac{4}{3}(6)+ \textit{b}}$

−8 = −8 + b
0 = b

$\ y \ = \ -\frac{4}{3}x \ + \ 0 \text{ or } y \ = \ -\frac{4}{3}x$