(x/12)+(x/8)
=(x*1/12)+(x*1/8)
=(1/12+1/8)*x
=(2/24+3/24）*x
=5/24x
(x/12)+(x/8)=8
(x*1/12)+(x*1/8)=8
(2/24+3/24）*x=8
5/24x=8
x=8*24/5
x=192/5