Given:
Amanda sold 13 rolls of plain wrapping paper and 12 rolls of holiday wrapping paper for a total of $208.
And,
Mofor sold 4 rolls of plain wrapping paper and 3 rolls of holiday wrapping paper for a total of $55.
Let, x be the cost of one roll of plain wrapping paper and y be the cost of one roll of holiday wrapping paper.
The equations are,

Solve the equations,

Put the value of y in equation (2),

Answer:
The cost of one roll of plain wrapping paper is x = $4.
The cost of one roll of holiday wrapping paper is y = $13.