Per cortesia,il problema n 451 e 452....sono in difficoltà
452) A+B=1/12 A+C=1/15 B+C=1/20 1/15-C+1/20-C=1/12 C=1/60=1lavoro in 60gg
B=1/20-1/60=1/30 A=1/20 A+B+C=1/60+1/20+1/30=(1+2+3)/60=6/60=1/10
y+z=30+x x-8=y-2=z+2+8 x-8=z+10 y-2=z+10 x=z+18 y=z+12
z+12+z=30+z+18 z=36 x=36+18=54 y=36+12=48