Let

x = the cost of one drink

y = the cost of one pizza

You spend $45.25 for 3 drinks and 2 pizzas means:

3x + 2y = 45.25

You spend $122.75 for 5 drinks and 6 pizzas means:

5x + 6y = 122.75

We have the following system of equations:

3x + 2y = 45.25

5x + 6y = 122.75

........

click here to see the system of equations solved for x and y

........

x = $3.25

y = $17.75

The drink costs $3.25 and the pizza costs $17.75.