6(1-у)-8(3у+1)+30у>-5
6-6у-24у-8+30>-5
28-6у-24у>-5
28-30у>-5
-30у>-5-28
-30у>-33
у<11
10
(2/3 + 7/12) = (8/12 + 7/12) = 15/12
16/25 * 15/12 = 4/5 * 3/3 = 4/5
9/10:15/16 = 9/10 * 16/15 = 144/150 = 72/75
4/5 - 72/75 = 60/75 - 72/75 = -12/75
-12/75 = -4/25 = -0.16
2*4*7cm+4*21cm=8*7cm+4*21cm=56cm+84cm=140cm
2 ч 35 мин 76 с- 5 мин 35 с= 2 ч 30 мин 41с