SOLUTION: The problem is, A grocery store knows that if it sells its canned hams for 5$ each, it can sell 750 per month, and if it sells the same hams for 9$, it will sell 600 per month. Ass

Algebra ->  Human-and-algebraic-language -> SOLUTION: The problem is, A grocery store knows that if it sells its canned hams for 5$ each, it can sell 750 per month, and if it sells the same hams for 9$, it will sell 600 per month. Ass      Log On


   

Question 976756: The problem is, A grocery store knows that if it sells its canned hams for 5$ each, it can sell 750 per month, and if it sells the same hams for 9$, it will sell 600 per month. Assuming the relationship between price and sales is linear, write the equation you could use to predict sales for other prices. Iv worked on this problem for 3 hours now and iv got the answer because my summer packet has answers but I dont get how to do it. Iv tried making slopes equations but nothing works. Please help, and thank you.
Answer by josgarithmetic(39623) About Me  (Show Source):
You can put this solution on YOUR website!
x, sales price
y, hams sold in the month

Linear points are (5,750) and (9,600).

slope %28600-750%29%2F%289-5%29=-150%2F4=-75%2F2-----(fixed mistake)

Pick a point to use in point-slope equation form, (9,600), but the other point can be chosen instead.
y-600=-%2875%2F2%29%28x-9%29
y=-%2875%2F2%29%28x-9%29%2B600
y=-%2875%2F2%29x%2B%2875%2F2%29%2A9%2B600
y=-%2875%2F2%29x%2B675%2F2%2B600-----
y=-%2875%2F2%29x%2B%28675%2B1200%29%2F2
highlight%28y=-%2875%2F2%29x%2B1875%2F2%29------Now fixed mistake

If sales in the month means revenue, then y%2Ax would be this revenue. This is %28howManyHamsSold%29%28pricePerHam%29.

Revenue, cross%28%28-75x%2B1275%29x%29
cross%28-75x%5E2%2B1275x%29
(Revenue part not fixed yet)