Answer:
y = 2x - 3
Step-by-step explanation:
The graph is a straight line, thus linear with equation
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m = 
with (x₁, y₁ ) = (3, 3) and (x₂, y₂ ) = (6, 9) ← 2 points on the line
m =
=
= 2 , thus
y = 2x + c ← is the partial equation
To find c substitute either of the 2 points into the partial equation
Using (3, 3 ), then
3 = 6 + c ⇒ c = 3 - 6 = - 3
y = 2x - 3 ← equation relating x and y