Respuesta :

I'd suggest starting by finding and using the LCD to eliminate the fractions 1/4 and 1/5.  The LCD here is 20.

Mult. all 3 terms by 20, we get 240 - 5x = 4x.  The 240 = 9x, and x = 26 2/3.
suspho
12 - x/4 = x/5
12 = x/4 + x/5
12 = (5x + 4x)/20
12 = (9x)/20
x = 12 * 20/9
x = 240/9
x = 80/3