Question

Write the equation of a line that passes through the points (−3, 7) and (3, 3)

Answer 1

Step-by-step explanation:

You can write an equation of a line conveniently by point-slope form. It's in the form of $y -a = m(x -b)$ where $(b,a)$ is the coordinates of a point that's on the line and $m$ is the slope of the line.

Now choose a point (It doesn't really matter which one) and plug that in the equation. I'll choose $(-3,7)$ where $a = 7$ and $b = -3$

$y -a = m(x -b) \\ y -7 = m(x -(-3)) \\ y -7 = m(x +3)$

The next thing we have to do now is finding the slope, $m$, where it's equal to $\frac{y_{2} -y_{1}}{x_{2} -x_{1}}$. I'll make $(-3,7)$ point 1 and $(3,3)$ point 2.

$m = \frac{3 - 7}{3 -(-3)} \\ m = \frac{3 - 7}{3 +3} \\ m = \frac{-4}{6} \\ m = -\frac{2}{3}$

Now let's plug that to our equation.

$y -7 = m(x +3) \\ y -7 = -\frac{2}{3}(x +3)$

Now we have the equation but out of all the choices it seemed that all of them are in slope-intercept form all you have to do now is make our equation rewrite it in slope-intercept form.

$y -7 = -\frac{2}{3}(x +3)\\ y -7 = -\frac{2}{3}x -\frac{2}{3}(3) \\ y - 7 = -\frac{2}{3}x -2\\ y = -\frac{2}{3}x +5$

Answer:

$y = -\frac{2}{3}x +5$ is your equation.