SOLUTION: Need another question validated please.
Bill and Mary are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of holiday wr
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-> SOLUTION: Need another question validated please.
Bill and Mary are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of holiday wr
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Question 1119862: Need another question validated please.
Bill and Mary are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of holiday wrapping paper. Bill sold 4 rolls of plain wrapping paper and 2 rolls of holiday wrapping paper for a total of $86. Mary sold 12 rolls of plain wrapping paper and 5 rolls of holiday wrapping paper for a total of $243. What is the cost each
of one roll of plain wrapping paper and one roll of holiday wrapping paper?
What I did to solve:
Let x= represent price of plain wrapping paper
Let y= represent price of holiday wrapping paper
4x + 2y = 86
12x + 5y = 243
3(4x + 2y) = 3(86)
-1(12x + 5y) = -1(243)
12x + 6y = 258
-12x - 5y = 243
---------------
1y = 15
4x + 2(15) = 86
4x + 30 = 86
4x + 30 - 30 = 86 - 30
4x = 56
4x = 56
-- --
4 4
x = 14
The part that is throwing me of is 1y = 15. It doesn't seem right.
Thanks for your time.
You can put this solution on YOUR website! Bill and Mary are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of holiday wrapping paper. Bill sold 4 rolls of plain wrapping paper and 2 rolls of holiday wrapping paper for a total of $86. Mary sold 12 rolls of plain wrapping paper and 5 rolls of holiday wrapping paper for a total of $243. What is the cost each
of one roll of plain wrapping paper and one roll of holiday wrapping paper?
x = cost of 1 roll of plain.
y = cost of 1 roll of hoiday.
equations are:
4x + 2y = 86 for bill.
12x + 5y = 243 for mary.
multiply both sides of the first eqution by 3 and leave the second equation as is to get:
12x + 6y = 258 for bill.
12x + 5y = 243 for mary
subtract the second equation from the first to get:
y = 258 - 243 = 15.
replace y with 15 in either of the original equations to solve for x.
i did:
4x + 2y = 86 for bill becomes 4x + 30 = 86 which becomes 4x = 56 which becomes x = 14.
you have x = 14 and y = 15.
replace x and y in both your original equations to confirm the solution is corre4ct.
4x + 2y = 86 for bill becomes 4*14 + 2*15 = 86 which becomes 56 + 30 = 86 which becomes 86 = 86 which is true.
12x + 5y = 243 for mary becomes 12*14 + 5*15 = 243 which becomes 168 + 75 = 243 which becomes 243 = 243 which is true.
both original equations are true when x = 14 and y = 15, therefore that solution looks good.
not sure why it's throwing you.
it's correct.
x and y represent the cost of 1 roll of plain and 1 roll of holiday.
You can put this solution on YOUR website!
Need another question validated please.
Bill and Mary are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of holiday wrapping paper. Bill sold 4 rolls of plain wrapping paper and 2 rolls of holiday wrapping paper for a total of $86. Mary sold 12 rolls of plain wrapping paper and 5 rolls of holiday wrapping paper for a total of $243. What is the cost each
of one roll of plain wrapping paper and one roll of holiday wrapping paper?
What I did to solve:
Let x= represent price of plain wrapping paper
Let y= represent price of holiday wrapping paper
4x + 2y = 86
12x + 5y = 243
3(4x + 2y) = 3(86)
-1(12x + 5y) = -1(243)
12x + 6y = 258
-12x - 5y = 243
---------------
1y = 15
4x + 2(15) = 86
4x + 30 = 86
4x + 30 - 30 = 86 - 30
4x = 56
4x = 56
-- --
4 4
x = 14
The part that is throwing me of is 1y = 15. It doesn't seem right.
Thanks for your time.
You did everything correctly, and 1y = 15 is the same as y = 15. The coefficient on all variables without a noticeable coefficient is 1, OR,
you can just easily DIVIDE each side by 1, as follows: , but that's taking it to the extreme because ANYTHING divided by 1 is ITSELF.
