(3а - 1)((1 1/5 + 1/3) : 4 3/5) + 1/3 < 7( 2 - 4 1/2 : 2 1/10)a =
= (3a - 1) (23/15 : 23/5) + 1/3 < 7(2 - 2 1/7)a =
= (3a - 1) * 1/3 + 1/3 < 7(-1/7)a =
= a - 1/3 + 1/3 < - 1a =<u> a < - a</u>
Решение:
cos 5*π/6 = - cos (π - 5*π/6) = - cos π/6 = - √ 3 / 22) sin (-7*π/4) = sin (-7*π/4 + 2*π) = sin π/4 = √ 2 / 23) tg 11*π/3 = tg(11*π/3 - 4*π) = tg (-π/3) = - tg π/3 = - √ 34) ctg (-3,5*π) = ctg (-3,5*π + 4*π) = ctg π/2 = 0
Х:420=13 256 - 3314*4
х:420=13 256-13256
х:420=0
х=0
(1512-504*3)+а=12447:27
(1512-1512)+а = 461
а=461