Question 521566
x/12+x/9=1
9x/108+12x/108=1
21x/108=1
21x=108
x=108/21
x=9*12/3*7=
x=3*12/7
x=36/7
x=5 1/7
check
36/7/12+36/7/9=1
3/7+4/7=1
1=1
ok