What is the equation of a line with a slope of 3 and a point (3, 1) on the line? express the equation in the form of y=mx+b where m is the slope and b is the y-intercept.

y = 3x-8




Explanation:

The slope is 3, so m = 3

The given point is (3,1) meaning x = 3 and y = 1. The x coordinate is always listed first in an ordered pair. The general format is (x,y)

We'll use m = 3, x = 3 and y = 1 to find the y intercept

y = mx+b
y = m*x+b
1 = 3*3+b ... plug in m = 3, x = 3 and y = 1
1 = 9+b
1-9 = 9+b-9 ... subtract 9 from both sides
-8 = b
b = -8



So we're given m = 3 as the slope and we just found that b = -8 is the y intercept

So y = mx+b updates to y = 3x-8. This is the final answer.



Side Notes:
* The slope of 3 means rise/run = 3/1 indicating each time we go up 3, we move to the right 1
* The y intercept -8 is the location on the vertical y axis numberline where the graph crosses. The point (0,-8) is on this line.