SOLUTION: One grocery store charges $10.00 for 8 cans of soup. A second store charges $6.00 for 5 cans of soup, but you need to join a purchase club for $3.00 to buy them. Write the cost mod

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: One grocery store charges $10.00 for 8 cans of soup. A second store charges $6.00 for 5 cans of soup, but you need to join a purchase club for $3.00 to buy them. Write the cost mod      Log On


   



Question 998619: One grocery store charges $10.00 for 8 cans of soup. A second store charges $6.00 for 5 cans of soup, but you need to join a purchase club for $3.00 to buy them. Write the cost model equations for both stores and find the number of cans that makes the costs equal.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
n, number of cans of soup

One store: 10%2A%281%2F8%29%2An, although the store might not allow this way in practice.

Second store: 6%2A%281%2F5%29%2An%2B3

Those are the cost formulas, and you could assume the prices given were just a grouping for efficiency of stating the prices.

For what number of cans, n, will the costs at both stores be equal.
10%281%2F8%29n=6%281%2F5%29n%2B3
-
%285%2F4%29n=%286%2F5%29n%2B3
%285%2F4-6%2F5%29n=3
%2825%2F20-24%2F20%29n=3
%281%2F20%29n=3
highlight%28n=60%29

Sixty cans at each place.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

One grocery store charges $10.00 for 8 cans of soup. A second store charges $6.00 for 5 cans of soup, but you need to join a purchase club for $3.00 to buy them. Write the cost model equations for both stores and find the number of cans that makes the costs equal.
Cost of 1 can at the 1st store: 10%2F8, or $1.25
Cost of 1 can at the 2nd store: 6%2F5, or $1.20

Let number of cans that'll make the 2 stores' costs equal, be C
Then: highlight%28highlight%281.25C+=+1.2C++%2B+3%29%29
1.25C - 1.2C = 3
.05C = 3
C, or number of cans that'll make the 2 stores' costs equal = 3%2F.05, or highlight_green%2860%29