Question

River C is 300 Miles Longer than River D. If the sum of their lengths is 5,570 miles, what is the length of each river?

Answer 1

$x-\ length\ of\ river\ D\\ x+300-\ length\ of\ river\ C\\\\ 5570=x+x+300\\ 5570=2x+300\ \ \ | subtract\ 300\\5270=2x\ \ \ | divide\ by\ 2\\x=2635\\\\ River\ C\ is\ 2935miles\ long\ and\ river\ D\ 2635\ miles\ long.$