x/4+2x/3+x/6=1/2

first look for the least common denominator (LCD) of the denominators (4, 3 and 6)

LCD = 12
now multiply this 12 to all terms to have whole numbers and coefficients:
12*(x/4 + 2x/3 + x/6) = 12*(1/2)
3x + 8x + 2x = 6
13x = 6

solve for x by dividing 6 by 13.