[tex]a)\\\\2(x^2-3x-1)=2x^2-3x\\\\ 2 x^2-6x-2=2x^2-3x\\\\ 2 x^2-6x-2x^2+3x=2\\\\-3x=2\ \ |:(-3)\\\\x=-\frac{2}{3}[/tex]
[tex]b)\\\\ \frac{x}{3}- 2=2x -\frac{ x+3 }{6}\ \ |*6\\\\2x-12=12x-(x+3)\\\\2x-12=12x- x-3\\\\2x-12=11x -3\\\\2x-11x=-3+12\\\\-9x=9\ \ |:(-9)\\\\x=-1[/tex]
[tex]c)\\\\ \frac{3}{5}x-0,4=2*(0,75 - \frac{1}{5} x)+0,1 \\\\ \frac{3}{5}x-0,4=1,5 - \frac{2}{5} x +0,1\\\\ \frac{3}{5}x+\frac{2}{5}x =1,5 +0,1 +0,4\\\\\frac{5}{5}x=2\\\\x=2[/tex]
[tex]d)\\\\ \frac{1}{3}(x^2+x)+ \frac{2}{3} =2( \frac{2}{3} -2x)+11+ \frac{1}{3}x^2 \\\\\frac{1}{3}x^2+\frac{1}{3}x+\frac{2}{3}=\frac{4}{3} -4x+11+\frac{1}{3}x^2\\\\\frac{1}{3}x^2+\frac{1}{3}x+4x -\frac{1}{3}x^2=\frac{4}{3} +11 -\frac{2}{3}x\\\\4\frac{1}{3} =11\frac{2}{3}\\\\\frac{13}{3}x=\frac{35}{3}\ \ |*3\\\\13x=35\ \ |:13\\\\x=\frac{35}{13}=2\frac{9}{13}[/tex]
