[tex]1)\\\\2(1-5x)=x^2\\\\2-10x=x^2\\\\x^2+10x-2=0\\\\a=1,\ \ b=10,\ \ c=-2\\\\\Delta= b^2-4ac= 10^2-4*1*(-2)=100+8=108\\\\\sqrt{108}=\sqrt{36*3}=6\sqrt{3}[/tex]
tex]x_{1}=\frac{-b-\sqrt{\Delta }}{2a}=\frac{-10-6\sqrt{3}}{2*1}=\frac{2(-5-3\sqrt{3})}{2 }=-5-3\sqrt{3} \\\\x_{2}=\frac{-b+\sqrt{\Delta }}{2a}=\frac{-10+6\sqrt{3}}{2*1}=\frac{2( 3\sqrt{3}-5)}{2 }= 3\sqrt{3}-5[/tex]
