### Home > GB8I > Chapter 2 Unit 2 > Lesson INT1: 2.2.4 > Problem2-85

2-85.

Calculate the slope of the line passing through each pair of points below.

1. $(1, 2)$ and $(4, –1)$

• Review the Math Notes box in Lesson 2.1.4 on slope.

$\text{Slope }=\frac{\Delta y}{\Delta x}=\frac{-1-2}{4-1}=\frac{-3}{3}=-1$

1. $(7, 3)$ and $(5, 4)$

• See Hint (a):

1. $(–6, 8)$ and $(–8, 5)$

1. $(55, 67)$ and $(50, 68)$

1. Azizah got $1$ for the slope of the line through points $(1, 2)$ and $(4, –1)$. Explain to her the mistake she made and how to calculate the slope correctly.

• She should have gotten $−1$ for her slope.