Представьте десятичную дробь в виде обыкновенной и вычислите 0.2+1/7; 5/6-0,25; 23/25+0,4; 0,75-7/42.

1)0,2+1/7= 1/5 + 1/7 = 7/35 + 5/35 = 12/35
2)5/6-0,25=5/6-1/4=7/12

2/10 + 1/7 = 14/70 + 10/70 = 24/70 = 12/35, 5/6 — 25/100 = 5/6 — 1/4 = 20/24 — 6/24 = 14/24 = 7/12, 23/25 + 4/10 = 92/100 + 40/100 = 132/100 = 1 32/100= 1 8/25, 75/100 — 7/42 = 3/4 — 1/6 = 18/24 — 4/24 = 14/24 = 7/12