Question

The graph represents revenue in dollars as a function of greeting cards sold.

A coordinate plane showing Greeting Card Revenue, Number of Cards Sold on the x-axis and Revenue in dollars on the y-axis. A line starts at (0. 0) and passes through (2, 8), (4, 16), and ends at (5, 20).

Which equation represents the function shown on the graph?

y = x
y = x
y = 2x
y = 4x

Answer 1

y = mx is the general form for a linear equation

so we would need to find the appropriate m-value for this equation

take any two points from the graph
for example, (0, 0) and (2, 8)

and apply the slope formula to get your m-value. once you have that m-value, plug it into y = mx + b to get your equation