A pizza company charges $50.40 for 3 pizzas and 12 drinks. A pizza is $10.80 more than a drink. What is the cost of each drink?
1.
$1.20
2
$1.50
$2.40
$2.50

A drink costs $1.20

Step-by-step explanation:

Step 1:  Make a system of equations

50.40 = 3p + 12d

p = 10.80 + d

Step 2:  Plug in p for the other equation

50.40 = 3(10.80 + d) + 12d

50.40 = 32.40 + 3d + 12d

50.40 - 32.40 = 15d + 32.40 - 32.40

18 / 15 = 15d / 15

1.20 = d

 A drink costs $1.20

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents