Answer:
Dale = 18 messages
Yolanda = 24 messages
Tony = 72 messages
Step-by-step explanation:
Total messages send = 114 --------------------------------------(1)
Let Dale send = x messages ---------------------------------(2)
Therefore Yolanda send = ( 6 + x ) messages ---------(3)
Therefore, Tony send = 3( 6 + x ) messages ------------(4)
Thus equating (1),(2),(3) and (4), we get
x + ( 6 + x ) + 3( 6 + x ) = 114
x + 6 + x + 18 + 3x = 114
5x +18 = 114
∴ x = 18
Dale send messages = x = 18 messages
Yolanda send messages = ( 6 + x )
= 6 + 18 = 24 messages
Tony send messages = 3( 6 + x )
= 3 x 24 = 72 messages