1) 3tg(x-π/3)= -√3, tg(x-π/3)= -√3/3= -1/√3,
x-π/3= -π/6+πk, k∈Z, x=π/3-π/6+πk=π/6+πk, k∈Z
2) 3ctgx+1=0, 3ctgx= -1, ctgx= -1/3, x=arcctg(-1/3)+πk, k∈Z
D=144-80=64 корень из D=8
X1=8+8/4=4, X2=8-8/4=0
49+14-35 не равно 0
25+10-35=0 верно
1) 2,3,4,5,6,7,8,9,10=54
2)1=20 2=22 3=24
20+22+24=66
22*24=528
10b^2+14b-15b-21+21= 10b^2-b= b(10b-1);
b=0. 10b-1=0
10b=0
b=0,1. Ответ: 0;0,1.