5/35+3 7/12-2а, при а =1,8
5/35+3 7/12-2×1,8=1/7+43/12-3,6=
=(1×12+43×7)/12-3,6=(12+301)/12-3,6=
=313/12-3 6/10=313/12-36/10=
=(313×5-36×6)/60=(1565-216)/60=
=1349/60=22 29/60
5/35+3 7/12-2а, при а =1,8
5/35+3 7/12-2×1,8=1/7+43/12-3,6=
=(1×12+43×7)/12-3,6=(12+301)/12-3,6=
=313/12-3 6/10=313/12-36/10=
=(313×5-36×6)/60=(1565-216)/60=
=1349/60=22 29/60