The way you typed it ....
multiply each term by 5x the LCD
8 + 4x = 12x^2 - 13x
12x^2 - 17x - 8 = 0
use the quadratic formula to find 2 answers
what you probably meant:
8/(x+4) = 12/(5x-13)
40x - 104 = 12x + 48
28x = 152
x = 152/28 = 38/7
8/x+4 = 12/5x - 13 (solve the proportion)
2 answers
152