Answer:
Thus, the price of each sandwich is $1 and each soda $0.50.
Explanation:
Let:
x: price of sandwiches
y: price of sodas
Now, write the equations for the amount that Mary paid on Monday and Tuesday for sandwiches & sodas:
Monday:

Tuesday:

When adding Tuesday equation from Monday equation, we found that x = 1. This value can be substituted into one of the equations. By substituting into Monday equation:

Now, let's solve the equation with one variable:


= 2 [/tex]

Thus, the price of each sandwich is $1 and each soda $0.50.