Answer: Melissa sent 11 messages
Dale sent 68 messages
Brian sent 17 messages
Explanation:
Let m = number of messages sent by Melissa
Let d = number of messages sent by Dale
Let b = number of messages sent by Brian
Melissa, Dale, and Brian sent a total of 96 text messages over their cell phones during the weekend. This means that
m + d + b = 96 - - - - - - 1
Brian sent 6 more messages than Melissa. This means
b = m + 6 - - - - - - 2
Dale sent 4 times as many messages as Brian. It means
d = 4b
Substituting m = b - 6 and d = 4b into equation 1, it becomes
b - 6 + 4b + b = 96
6b = 96 + 6 = 102
b = 102/6 = 17
d = 4b = 4× 17 = 68
m = b - 6 = 17 - 6 = 11