Answer:
The cost of a drink is $1.5
Explanation:
Let x be the cost of 1 hot dog , y be the cost of 1 drink and z be the cost of 1 pretzel
We are given that The Smith family purchased 3 hot dogs, 1 drinks, and 4 pretzels for $19.50.
So, 3x+y+4z=19.50 ---1
We are also given that The Garcia family bought 3 hot dogs, 2 drinks, and 2 pretzels for $15.
So, 3x+2y+2z=15 ---2
We are also given that The Jones family spent $10.00 on 2 hot dogs, 2 drinks, and a pretzel.
2x+2y+z=10 ---3
Substitute the value of y from 1 in 2 and 3
3x+2(19.50-3x-4z)+2z=15 and 2x+2(19.50-3x-4z)+z=10
-3x-6z+24=0----4 and -4x-7z+29=0 ---- 5
Substitute the value z from 4 in 5
![-4x-7((-24+3x)/(-6))+29=0](https://img.qammunity.org/2021/formulas/mathematics/high-school/nt97hpwbcbcco0wlduvd1hj8n5mddwdwjg.png)
x=2
Substitute the value of x in 4
-3(2)-6z+24=0
z=3
Substitute the value of x and z in 1
3(2)+y+4(3)=19.50
y=1.5
Hence the cost of a drink is $1.5