Lindsey B. answered 11/04/19
Secondary Math Teacher with a Master's Degree in Math Education!
When you are given two coordinates you have to first find the change in y and the change in x, which is your slope. The change in y is 5 since the first y coordinate is 1 and the second y coordinate is 6 (6 - 1 = 5)
The change in x is 3 since the first x coordinate is 3 and the second x coordinate is 6. (6 - 3 = 3)
This means that your slope (m) is 5/3
Then you pick one coordinate and plug in x and y with m to the linear equation format y = mx + b:
I am going to use (3,1): 1 = 5/3(3) + b
Then you solve for b. When multiplying a fraction to a whole number you just multiply to the numerator since 5 is the same as 5/1 and when you multiply fractions you go straight across. This means that:
1 = 15/3 + b
15/3 = 5, so 1 = 5 + b
-5 -5
-4 = b
When you write your final linear equation you only plug in m (slope) and b (y intercept):
y = 5/3x - 4