This week I learned one more equation of lines – m(x-x)=y-y and I also learned rate of change.
In this question, first, we need make sure which one is dependent number(y) and which one is independent number(x). Earned dependent on sale. Then, we need figure out the slope. We use the slope formula, the slope is 0.08(8%). The slope represents that for every dollar sold, he earns 0.08$. The equation of y-intercpet is y=0.08x+340.