The graph of a linear relationship passes through 0,3 and 3,9 which is an equation for this linear relationship

Answer 1

slope M = (9-3)/(3-0) = 6/3 = 2

B = y - mx = 3 - (2)(0) = 3 - 0 = 3 <--- using (0,3), so x=0 and y = 3 which is the y-intercept

y = 2x + 3

Answer 2

First find the slope from

m = (y₂ - y₁)/(x₂ - x₁)

Then write the equation in point slope form, either

y - y₁ = m(x - x₁)

or

y - y₂ = m(x - x₂)

You have 2 ordered pairs (x₁,y₁) and (x₂,y₂). Just plug in the numbers.