-1+1=0!!!!!!!!!!!!!!!!!!!
3,25 + 0,5у + 1,3 + 0,8у = 5,9
0,5у + 0,8у = 5,9 - 3,25 - 1,3
1,3у = 1,35
у = 1,35 : 1,3
у = 135/130
у = 1 5/130
у = 1 1/26
( ( 5X - 3) / 3 ) - 1 = ( 5X - 3 - 3) / 3 = ( 5X - 6) / 3
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(5X - 6)*12 = ( 5X - 3)*3
60X - 72 = 15X - 9
60X - 15X = - 9 + 72
45X = 63
X = 1.4
2sin(2x/3) ≤ -1
sin(2x/3) ≤ -1/2
4π/3 + 2πn ≤ 2x/3 ≤ 5π/3 + 2πn, n∈Z |*3/2
2π+2πn ≤ x ≤ 2,5π+2πn, n∈Z
[2π+2πn ; 2,5π+2πn] , n∈Z
2cos(3π-x/4)+3sin(π/2-x/4)<0
-2cos x/4 + 3cos x/4 <0
cos x/4 <0
π/2 + 2πn < x/4 < 3π/2 + 2πn, n∈Z |*4
2π+4πn < x < 3π + 4πn, n∈Z
(2π+4πn; 3π + 4πn), n∈Z