### Home > INT1 > Chapter 3 > Lesson 3.1.4 > Problem3-48

3-48.

Write the equation of each line described below:

1. A line that goes through the points $(–7, 10)$ and $(1, 4)$.

Review the Math Notes box in Lesson 2.3.2.

Substitute the slope in for $m$ and one set of coordinates, say $(1, 4)$, in for $x$ and $y$. Then solve for the $y$-intercept $(b)$.

$\text{ Recall that slope = }\frac{\text{rise}}{\text{run}}=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

$\text{Slope = }\frac{10-4}{-7 -1}=\frac{6}{-8}=-\frac{3}{4}$

$y=mx+b$

$4=-\frac{3}{4}\cdot 1+b$

$4=-\frac{3}{4}+b$

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

2. A line with a slope of $-\frac{3}{4}$ that passes through the point $(–14, 4)$.

See part (a).

3. A line with a slope of $0$ that passes through the point $(6, –11)$.

See part (a).