Вычислите (3/7-1 1/3)*21/86 :7 2/5

Question

Вычислите (3/7-1 1/3)*21/86 :7 2/5

Answer 1

(3/7-1 1/3)*21/86 :7 2/5=
1)3/7-1 1/3=3/7-4\3=37−43=3 · 33 · 7−7 · 47 · 3=921−2821=9 − 2821=−19\21 
2)19\21*21\86=19\86
3)19\86:7 2\5=19\86:37:5=1986÷375=1986·537=19 · 586 · 37=95\3182