At a restaurant, you eat 2 taco salads and drink 2 glasses of iced tea. Your friend eats 1 taco salad and drinks 1 glass of ice tea. You get charged $11 and your friend $6.50. Can you determine the price of taco salads and iced tea? Explain.

Let x be taco salads, and y be drinks.

The equations are as follows:

1) 2x+2y=11

2) x+y=6.50

Use 2) to isolate for a variable, for example:

3) y=6.50-x

Using 3), substitute it back into 1) to solve for x.

2x+2 (6.50-x) = 11

2x-2x+13=11

The x's cancel out, leaving you with:

13=11

This is not true, and therefore you cannot determine the prices of the taco salads or iced tea.