A. 7/4
Rate of change is the same as slope, it is how the line has to go to get from the first to the second point. The slope function is y2-y1 / x2-x1. So we end up with 8-1/5-1 making 7/4
10 because 10x1 is 10 and 5x2 is 10 which is the lowest common denominator for both.
You worded this weird, but each bag of sugar is 8 pounds...
24 dollars kid!!! You really need other numbers to help with but yeah