3/8у+у-1/4у=3/8*2 2/3+2 2/3-1/4*2 2/3
=3/8*8/3+8/3-1/4*8/3=24/24+8/3-8/12=12/12+32/12-8/12=36/12=3
3/8*4/9+4/9-1/4*4/9=12/72+4/9-4/36=6/36+16/36-4/36=18/36=1/2
(24960:(300(200—6х):115))=8
300(200-6x):115 = 24960 : 8
300(200-6x):115=3120
300(200-6x)=3120*115
300(200-6x)=358800
200-6x=358800:300
200-6x=1196
6x=200-1196
6x=-996
x=-996:6
x = -166