Answer:
f(x) = 3x
Step-by-step explanation:
The equation of a line passing through the origin is
y = mx ( m is the slope )
Calculate m using the slope formula
m =
with (x₁, y₁ ) = (0, 0) and (x₂, y₂ ) = (1, 3)
m = = 3 , then
y = 3x ← is the equation of the graphed line