Номер 1246

Обчисли:

1) –6,3 • 1/7 • (–1/12) • 8,4 = –6 3/10 • 1/7 • (–1/12) • 8 2/5 = –63/10 • 1/7 • (–1/12) • 42/5 = (–63/10 • 42/5) • (1/7 • (–1/12) = (–63/10 • 42/5) • (–1/84) = (–1323/25) • (–1/84) = 63/100 = 0,63

2) –1 13/15 • (–0,625) • (–5 2/5) = –28/15 • (–625/100) • (–27/5) = (–28/15 • (–5/8) • (–27/5) = (–28/15 • ((–5/8) • (–27/5)) = –28/15 • 27/8 = –63/10 = –6,3

3) 2,5 • (–4,2) • 3 1/3 • 8/35 = –10,5 • (10/3 • 8/35) = –10,5 • 16/21 = –10 1/2 • 16/21 = –21/2 • 16/21 = –8

4) –1,8 • (–1 2/3) • (–2 1/7) • (–4 2/3) = (–1 4/5) • (–1 2/3) • (–2 1/7) • (–4 2/3) = (9/5 • 5/3) • (15/7 • 14/3) = 3 • 10 = 30