x-suma initiala
1/4 din x= 1/4 * x= x/4 -prima data
x-x/4= (4x-x)/4= 3x/4 -restul
1/6 din 3x/4= 1/6 * 3x/4= 1/2 *x/4= x/8 -a doua oara
3x/4- x/8= (6x-x)/8= 5x/8- noul rest
1/3 din 5x/8 +120 = 1/3 * 5x/8= 5x/24 +120 -a treia oara
5x/8 -5x/24 -120= (15x-5x-2880)/24= (10x-2880)/24 -noul nou rest
(10x-2880)/24=600
10x-2880=600*24
10x-2880=14400
10x=14400+2880
10x=17280
x=1728