3/x + 5x/12 = 9/4.... i need to solve for x but i don't know what im doing.. can someone help me please

multiply each term by 12x, which will cancel each of the denominators giving you

36 +5x^2 = 27x
5x^2 - 27x + 36 = 0
(5x-12)(x-3) = 0
x = 12/5 or x = 3