\begin{lgathered}cos(-570)+ \sqrt{3}sin(-300)+2tg(-135)= \\\ =cos(2\cdot360-570)+ \sqrt{3}sin(360-300)+2tg(180-135)= \\\ =cos150+ \sqrt{3}sin60+2tg45=- \frac{\sqrt{3}}{2} +\sqrt{3}\cdot\frac{\sqrt{3}}{2}+2\cdot1= \\\ =- \frac{\sqrt{3}}{2} +\frac{3}{2}+2=3.5- \frac{\sqrt{3}}{2}\end{lgathered}cos(−570)+√3sin(−300)+2tg(−135)= =cos(2⋅360−570)+√3sin(360−300)+2tg(180−135)= =cos150+√3sin60+2tg45=−2√3+√3⋅2√3+2⋅1= =−2√3+23+2=3.5−2√3