Question

Complete the equation of the line through (2, 1) and (5, -8). Use exact numbers.

Linear equations and graphs
Complete the equation of the line through (2, 1) and (5, -8). Use exact numbers.

2021-02-17

First, we find the slope: $$\displaystyle{m}=\frac{{{y}{2}-{y}{1}}}{{{x}{2}-{x}{1}}}=\frac{{-{8}-{1}}}{{{5}-{2}}}=-\frac{{9}}{{3}}=-{3}$$
Use the slope-intercept form of a line and substitute the slope and a point, say (2,1) to find b: $$y=mx+b$$
$$1=-3(2)+b$$
$$1=-6+b$$
$$7=b$$
So, the equation of the linear function is $$y=-3x+7$$