Answer:
y=4x
Step-by-step explanation:
The equation of a line is y=mx+b, where m is the slope and b is the y intercept.
The slope formula is Δy/Δx, so using the coordinates (1, 4) and (2, 8), the slope is [tex]\frac{8-4}{2-1}[/tex] which equals 4.
The y intercept is 0.
Therefore, the equation is y=4x.