Using the formula from part a, calculate the retail price for each quantity range. (2 points) quantity 0-20 pairs 21-40 pairs 41-60 pairs 61-80 pairs 81 or more
pairs wholesale price 
(per pair) $25.00 each $23.00 each $21.00 each $19.00 each $17.00 each retail price 
(per pair)

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.