Help and the answer is not 16 or 18!

Hey peepeeepuupuu! Do you know how to find the equation of a line given two points on the line? If not, follow the following steps. The slope of the line is $m=\frac{y_2-y_1}{x_2-x_1}$ where $(x_1, y_1)=(-1, 7)\:and\:(x_2, y_2)=(3, -2)$. Write the line in the form $y-y_1=m(x-x_1)$ . Replace $y_1\:and\:x_1$with the points and leave x and y as they are. M is the slope. From there you will get the equation of your line. After you get the equation plug in -6 as x into it and you'll get your answer.

Any questions about my (long and confusing) explanation, just ask!