To determine which equation matches the graph you have to calculate the slope of the linear relationship.
Note that the line starts in the origin (0,0), this means that the y-intercept is zero and the formula for the line is y=mx, where m=slope
For this you need to use two points if the given line, I'll use the two that are marked with the dots.
Upper point- Point 1 (3,9)
Lower point- Point 2 (1,3)
The formula you have to use is:
[tex]m=\frac{Y_1-Y_2}{X_1-X_2}=\frac{9-3}{3-1}=\frac{6}{2}=3[/tex]
The slope of this proportional relationship is m=3
The formula for this graph is then C. y=3x
