Question

Write an equation for the line perpendicular to y = –3x + 6 that contains (7, –4).

Answer 1

Hey!

So we are given that the two lines (the one you are trying to find and the other one whose equation you have been given) are perpendicular. This means that their slopes are the negative reciprocal of each other. Since the slope of the line you have been given is -3 the slope of the line that you need to find is 1/3. Using this and the point we have been given we can find the y-intercept.

-4 = (1/3)(7) + b

-4 = 7/3 + b

-19/3 = b

Since we know both the slope and the y-intercept we can write out equation:

y = (1/3)x - 19/3