alegebra 1
posted by jessica on .
how do you Find the slope of graphs and linear equations???
like (3,5) and(2,2)
how do i solve that

Given two points, the slope is easy: it's the difference in the ys divided by the differences in the xs.
Just be careful to get the numbers in the right order and careful of the signs.
For example, (3,5) and(2,2)
x1=3
x2=2
y1=5
y2=2
So the slope is
(y1  y2)/(x1  x2)
= (5  (2)) / 3  2
= (5 + 2) / 1
= 7
We can go on from there to get the equation of the line:
y = mx + c , where m is the slope
y = 7x + c in this case
But what is c? Well, we substitute any point on the line for x and y, and
5 = 7*3 + c
5 = 21 + c
c = 16
So the line is
y = 7x  16