if (frac{4m+3n}{4m-3n}=frac{5}{2}), find the ratio m:n
-
A.
7:4 -
B.
4:3 -
C.
3:4 -
D.
4:7
Correct Answer: Option A
Explanation
(frac{4m + 3n}{4m – 3n} = frac{5}{2})
(5(4m – 3n) = 2(4m + 3n))
(20m – 15n = 8m + 6n)
(20m – 8m = 6n + 15n)
(12m = 21n)
(frac{21}{12} = frac{m}{n})
(m : n = 7 : 4)