How do you write an equation of a line given (3, 5) and (-6, -1)?

1 Answer
Aug 14, 2017

Find the gradient and the y-intercept in y=mx+c to get

3y=2x+9

Explanation:

y=mx+c is the slope-intercept equation of any straight line. So we need to find m, the gradient of the line, and c, the y-intercept.

m=y2y1x2x1

y2 being the second y value, which is 1, and y1 is 5. The same goes for x2 and x1, so

m=1563

m=69=23

Since

y=mx+c

to find c do

c=ymx

We substitute one of the coordinates, for eg. (3,5), so

c=5(23)3

c=3

Therefore, we substitute the values of m and c in y=mx+c
to get

y=23x+3

3y=2x+9