9.7k views
3 votes
What is the equation of a line that passes through (7,8) and has a slope of -3

What is the equation of a line that passes through (7,8) and has a slope of -3-example-1

2 Answers

2 votes
You use y=mx+b, then substitute -3 for the slope (m) and 7 for x and 8 for y, after you substitute all those things - use that equation to solve for the b-term - that will give you the y-intercept. Then you will rewrite the equation of the line as y=-3x+(whatever you just found for b). 
User Charo
by
5.5k points
3 votes
It is helpful to first plug this in to point-slope form (note that there are other ways to do this).

Using the form
y-y_1 = m(x-x_1), you get
y-8=-3(x-7). You can simplify this to get
y = -3x+29.

Answer choice A
User Amir Astaneh
by
5.7k points