Question

If (x-9): (3x+6) is the triplicate ratio of 4:9. Find X.

Answer 1

x-9 : 3x + 6 is the triplicate ratio of 4 : 9.
Hence $4^3:9^3=x-9:3x+6$
That is
$\frac{64}{729}=\frac{x-9}{3x+6}$
Ie,
$192x+384=729x-6561$
$537x=6945$
$\therefore x=\frac{6945}{537}$
Hence $x=\frac{2315}{179}$