How would you find y=mx+b when given (5,8) and (10, 14)?

1 Answer
Apr 7, 2015

In general, the slope of a line joining points (x_1,y_1) and (x_2,y_2) is
m = (y_2 - y_1)/(x_2 - x_1)

For the given values (x_1,y_1) = (5,8) and (x_2,y_2) = (10,14)
we have
m = (14- 8)/(10-5) = 6/5

Using (arbitrarily) (x_1,y_1) = (5,8) as a point
and (not arbitrarily) m=6/5 as the slope

The slope-point formula for the line can be written as
(y-8) = 6/5(x-5)

rarr 5y - 40 = 6x - 30
rarr 5y = 6x +10

We can convert this to slope-intercept form y=mx+b
by dividing both sides by 5

y = 6/5x + 2

The slope is 6/5 and the y-intercept is 2