Answer:
y = (1/2)x
Explanation:
Lets look for an equation of the form y = mx + b, where m is the slope and b is the y-intercept (the value of y when x = zero). We can find the slope by calculating the Rise/Run between the two given points:
Going from (0,0) to (8,4):
Rise = (4-0) = 4
Run = (8-0) = 8
Slope = Rise/Run (4/8) or (1/2)
The equation becomes y = (1/2)x + b
We need a value of b that forces the line through both points. The point (0,0) actually tells us that b is 0, since b is the value of y when x=0. If we weren't ask lucky to get a point where x is zero, we could cacalute b by putting either point in the above equation and solving for b:
y = (1/2)x + b
4 = (1/2)*(8) + b for (8,4)
b = 0
The equation is y = (1/2)x
See the attached graph.