If x:y =5:3 , then (8x-5y) : (8x +5y) =?
A
5 : 11
B
6 : 5
C
5 : 6
D
3 : 8
Correct Answer: 5 : 11
xy = 53⇒8x5y = 5×83×5⇒8x - 5y8x + 5y = 40 - 1540 + 15⇒8x - 5y8x + 5y = 2555⇒8x - 5y8x + 5y = 511