Irene R. answered 03/31/20
BS in Mechanical Engineering and Certified math teacher for 13 years
Hi Armani,
Let's use the variable d to represent the cost of one drink and the variable p represent the cost of one popcorn.
Now we can write two equations based on the info given in the problem:
10d + 5p = $118.75
9d + 10p = $157.75
These equations can be solved using elimination. Multiply the first equation by -2:
10d + 5p = 118.75 becomes -20d - 10p = -237.50
9d + 10p = 157.75
Now combine the two equations to find the value of d:
-20d - 10p = -237.50
9d + 10p = 157.75
-11d = -79.75
-11d/-11 = -79.75/ -11
d= 7.25
The cost of one drink is $7.25
You can also use either equation to find the value of p. Using the second equation, substitute 7.25 for d:
9d + 10p = 15775
9• 7.25 + 10•p = 157.75
65.25 + 10p = 157.75
65.25 + 10p - 65.25 = 157.75 - 65.25
10p = 92.50
10p/ 10 = 92.50/ 10
p = 9.25
The cost of one popcorn is $9.25
Hope this helps you Armani. Send a message is you need any lessons!