Question

A line intersects the points(-22,-14) and (-18,-12). What is the slope-intercept equation for this line?

Answer 1

Hello there,

Well we are going to start off with the equation to find the slope based on the given points:

                                                    $\frac{y_{2} - y_{1} }{x_{2} -x_{1} }$

Now using the two given points we are going to plug in and solve:

                                         $\frac{(-12)-(-14)}{(-18)-(-22)}$ = $\frac{2}{4}$ = $\frac{1}{2}$

From this you know that $\frac{1}{2}$ is the slope of the equation. However, to find the y-intercept we are going to use y = mx+ b and plug in one of the points to solve:

                                        (-14) = $\frac{1}{2}$ (-22) + b

                                        (-14) = (-11) + b

                                         -3 = b

That means that the y-intercept is at (0, -3). Lastly, we are just going to plug all this into the slope-intercept form:

                                       y = $\frac{1}{2}$ - 3

Hope I helped,

Amna