Calculați folosind ordinea efectuării operațiilor
a.(3/5+33/55+333/555): –(–5/7) –(–111/300):(1/3+1/30+1/300);
b.[(–2/3–1/9+10/5):13/18–5 1/3•(7/16–3/8)]–53/39
/ este supra