Let \( p \) represent the cost of a roll of plain wrapping paper, and let \( h \) represent the cost of a roll of holiday wrapping paper. Based on the sales information provided, we can set up the following system of linear equations:
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From Brandy's sales: \[ 2p + 1h = 43 \tag{1} \]
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From Jennifer's sales: \[ 7p + 1h = 93 \tag{2} \]
Now we will solve this system algebraically. We can start by isolating \( h \) in equation (1):
\[ h = 43 - 2p \tag{3} \]
Next, we substitute equation (3) into equation (2):
\[ 7p + (43 - 2p) = 93 \]
Simplifying this equation gives:
\[ 7p + 43 - 2p = 93 \]
Combining like terms:
\[ 5p + 43 = 93 \]
Subtracting 43 from both sides:
\[ 5p = 93 - 43 \]
\[ 5p = 50 \]
Dividing both sides by 5:
\[ p = 10 \]
Now that we have the cost of plain wrapping paper, we can substitute \( p = 10 \) back into equation (3) to find \( h \):
\[ h = 43 - 2(10) \]
\[ h = 43 - 20 \]
\[ h = 23 \]
Thus, the costs per roll of wrapping paper are:
- \( p = 10 \) (cost of plain wrapping paper)
- \( h = 23 \) (cost of holiday wrapping paper)
In summary:
- The cost of a roll of plain wrapping paper is $10.
- The cost of a roll of holiday wrapping paper is $23.