Find the equation of the line that passes through the points (1,1) and (3,5)

Answer 1

y-y₀ = m(x-x₀)

m = change-in-y/change-in-x = (5-1)/(3-1) = 4/2 = 2

You can pick either point to finish

y - 1 = 2(x-1)

y= 2x-2 +1

y = 2x-1

or

y-5 = 2(x-3)

y = 2x-6+5

y = 2x-1