### Home > CCA > Chapter 2 > Lesson 2.1.4 > Problem2-42

2-42.

Without graphing, find the slope of each line described below. Homework Help ✎

1. A line that goes through the points (4, 1) and (2, 5).

Use a slope triangle or another method to determine the slope of the line.

Another method is to first subtract the x-values and the y-values from each other.
Δx: 4 − 2 = 2
Δy: 1 − 5 = −4

$\frac{\Delta{\textit{y}}}{\Delta{\textit{x}}}=\frac{-4}{-2}= -2$

Substitute the differences into the slope formula.

2. A line that goes through the origin and the point (10, 5).

See part (a).

3. A vertical line (one that travels “up and down”) that goes through the point (6, −5).

Vertical lines have an undefined slope.

4. A line that goes through the points (1, 6) and (10, 6).

• See part (a).