Answer:
Christine: $25
Kareem: $18
Trey: $36
Step-by-step explanation:
Variables:
c = amount of money Christine has
k = amount of money Kareem has
t = amount of money Trey has
c = 7 + k
t = 2k
total amount of money = $79 = c + k + t
Write the equation in terms of k:
79 = (7 + k) + k + 2k
79 = 7 + 4k
72 = 4k
k = 18
Kareem has $18.
Since we found how much money Kareem has, we can find how much money everyone else has:
c = 7 + k
c = 7 + 18
c = $25
Christine has $25
t = 2k
t = 2(18)
t = $36
Trey has $36
Check to make sure the sum of all three people's money is $79:
18 + 25 + 36 = 79