9x-5/2-5x+3/3+1-4x/4=5
9х-5/2-5х+1+1-4х/4=5
4х-5/2+2-4х/4=5
4х-1/2-4х/4=5
16х-2-4х=20
12-2=20
12х=20+2
12х=22
х=11/6= 1 5/6
Sin(-240°) = -sin240° = - sin(180 + 60) = sin60° = √3/2
cos(-240°) = cos240° = cos(180 + 60) = -cos60° = 1/2
tan(-240°) = -tan240° = -tan(180+60) = -tan60° = -√3
cot(-240°) = -cot240° = -cot(180+60) = -cot60° = -1/√3
(a-4)^2-2a(5a-2)=a^2-8a+16-10a^2-4a=-9a^2-12a+16=
=-9\9+12\3+16=1+4+16=21
Ответ:21