150*х*3=1800, 12090-х=3090:30, а:30=768+987, ( х+240 ) * 3 - 360=540, 876+у+9869=78000

150*x*3=1800150x=1800/3x=600/150x=412090-x=3090/3012090-x=1030x=12090-1030x=11060a/30=768+987a/30=1755a=1755*30a=52650(x+240)*3-360=540(x+240)=540+360x+240=900/3x+240=300x=60876+у+9869=78000876+у=78000-9869876+у=68131у=68131-876у=67255