[tex]3x\left ( x-2 \right )-5x\left ( 1-x \right )-8\left ( x^{2} -3\right )[/tex]
[tex]\Leftrightarrow 3x^{2}-6x-5x+5x^{2}-8x^{2}+24[/tex]
[tex]\Leftrightarrow -11x+24[/tex]
1,(6x+1)^2+(6x-1)^2-2(1+6x)(6x-1)
[tex]\left ( 6x+1 \right )^{2}+\left ( 6x-1 \right )^{2}-2\left ( 1+6x \right )\left ( 6x-1 \right )
\Leftrightarrow \left ( 6x+1 \right )^{2}-2.\left ( 6x+1 \right )\left ( 6x-1 \right )+\left ( 6x-1 \right )^{2}[/tex]
[tex]\Leftrightarrow [\left ( 6x+1 \right )\left ( 6x-1 \right )]^{2}[/tex]
[tex]\Leftrightarrow \left ( 6x+1-6x+1 \right )^{2}[/tex]
[tex]\Leftrightarrow 4[/tex]