Respuesta :
Answer:
The cost of 1 drink = $4.1
The cost of 1 pretzel  = $4.22
Step-by-step explanation:
Let us assume the cost of 1 drink= $ m
And the cost of 1 pretzel = $ n
Now,  the cost of 3 drinks  = 3 x ( cost of 1 drink)  = 3 x ( $ m)  = 3 m
The cost of 10 pretzels  = 10 x ( cost of 1 pretzel)  = 10 x ($ n)  = 10 n
So, the total cost of  3 drinks + 10 pretzels  = 3 m +  10 n
Also, Isabella paid $54.50 fro 3 drinks and 10 pretzels.
⇒3 m +  10 n  = $54.50  .............  (1)
Again,  the cost of 9 drinks  = 9 x ( cost of 1 drink)  = 9 x ( $ m)  = 9 m
The cost of 5 pretzels  = 5 x ( cost of 1 pretzel)  = 5 x ($ n)  = 5 n
So, the total cost of  9 drinks + 5 pretzels  = 9 m +  5  n
Also, Jason paid $57.25 fro 9 drinks and 5 pretzels.
⇒9 m +  5 n  = $57.25  .............  (2)
Solving (1) and (2) fro the values of m, n .
Multiply equation (1) with (-3) and add with (2), Â we get:
9 m + Â 5 n - 9 m - 30 n = Â 57 . 25 Â - Â 162.75
or, - 25 n = -105. 5
or, n = 4.2
Solving for m : we get: Â 3 Â m + Â 10 ( 4.2) Â = 54.5, or m = 4.1
Hence, the cost of 1 drink = $4.1
And cost of 1 pretzel  = $4.22