2√3*(1+cos5π/6)/2-√3=√3+√3*cos(π-π/6)-√3=√3*(-cosπ/6)=
=-√3*√3/2=-1,5
1) (-17,8-x)-(y-100,4)=-17,8-x-y+100,4=82,6-x-y
2) (k-57,4)-(d-60 2/3) = k - 57 2/5 - d + 60 2/3 =k-d + (60 10/15 - 57 6/15) = k-d + 3 14/5
3) -t+30,1-(-k+310 3\9)=-t+30,1+k-310 1\3=k-t-10 7\30
4) -90,7-a-(81,4-b)=-90,7-a-81,4+b=b-a-172,1
<span>9×(2+y)-4y=6y-61
18+9y-4y=6y-61
18+5y=6y-61
5y-6y=-61-18
-y=-79
y=79</span>
532-х:2=227
х:2=532-227(в столбик)
х:2=305
х=305*2
х=610
532-610:2=227
227=227
Ответ: 610
вот