Answer: the total cost of this order is $14
Step-by-step explanation:
She sells 3 hot dogs and 2 pretzels for $15.00.
She sells 5 hot dogs and 1 pretzel for $21.50. The system of linear equations used to model the situation is
3h+2p=15 - - - - - - - - - - - -1
5h+p=21.5 - - - - - - - - - - -2
Multiplying equation 1 by 5 and equation 2 by 3, it becomes
15h + 10p = 75
15h + 3p = 64.5
Subtracting, it becomes
7p = 10.5
p = 10.5/7
p = 1.5
Substituting p = 1.5 into equation 1, it becomes
3h + 2 × 1.5 = 15
3h + 3 = 15
3h = 15 - 3 = 12
h = 12/3 = 4
If Tracy sells 2 hot dogs and 4 pretzels, the total cost of this order would be
(4 × 2) + (4 × 1.5)
= 8 + 6 = $14
