Answer: Shana bought 2 sodas.
Shana bought 5 bags of popcorn.
Step-by-step explanation:
Let S represent the number of sodas that Shana bought.
Let B represent the number of bags of popcorn that Shana bought.
Shana bought 7 things from the concession., all either sodas or bags of popcorn. This means that
S + B = 7
Sodas cost $3 each and popcorn cost $4 per bag. Shana spent a total of $26. This means that
3S + 4B = 26 - - - - - - - - - - - - -1
Substituting S = 7 - B into equation 1, it becomes
3(7 - B) + 4B = 26
21 - 3B + 4B = 26
- 3B + 4B = 26 - 21
B = 5
S = 7 - B = 7 - 5
S = 2