Troy and Lisa were shopping for school supplies. Each purchased different quantities of the same notebook and thumb drive. Troy bought 12 notebooks and 4 thumb drives for $100. Lisa bought 3 notebooks and 15 thumb drives for $249. Find the cost of each notebook and each thumb drive.

Sarah,

Let x = cost of notebook

let y = cost of thumbdrive

For Troy   5x + 5y = 75

For Lisa    2x + 6y = 78

Troy's equation let's divide it by 5 and get

x+ y = 15     multiply by -2

-2x -2y  = -30

2x + 6y = 78    Add equations

      4y = 48

Solve for y.  Then plug it in one of the original equations and solve for x.  Check by plugging into the other original equations

Step-by-step explanation:

36 is the final answer! : )

total amount of money that he should pay if he has not used his duty free exemption is $98

step-by-step explanation:

given a united states citizen returning to the states declares the following items at the customs office: 3 shirts at $8.50 each 2 dresses at $27.50 each 1 pair of gold cuff links at $17.50 per pair. we have to find how much he pay

cost of 3 shirts if one cost at $8.50 is

cost of 2 dresses if one cost at $27.50 is  

cost of 1 pair of gold cuff at $17.50

so, total amount of money that he should pay if he has not used his duty free exemption is   $25.5+$55+$17.50=$98