Answer:
Let x be the amount ( in dollars ) saved by Dan,
∵ Simone saved $65.35 more than her brother Dan,
∴ Amount saved by Simon = x + 65.35 ,
Now, Simon saved $37.50 less than her sister Carly,
⇒ amount saved by Carly - 37.50 = x + 65.35
⇒ Amount saved by Carly = x + 102.85
According to the question,
x + 102.85 = 127.75
Which is the required equation,
Subtract 102.85 both sides,
x = 24.9
Hence, Simon's saving = 24.9 + 65.35 = $ 90.25
While, Dan's saving = $ 24.9.