1)
[tex]2x^2+8x-10=0 \ \ /:2\\\\x^2+4x-5=0\\\\a=1, \ b=4, \ c=-5\\\\\Delta=b^2-4ac\Rightarrow4^2-4\cdot1\cdot(-5)=16+20=36\\\\\sqrt{\Delta}=\sqrt{36}=6\\\\x_1=\frac{-b-\sqrt{\Delta}}{2a}\Rightarrow\frac{-4-6}{2\cdot1}=\frac{-10}{2}=\boxed{-5}\\\\x_2=\frac{-b+\sqrt{\Delta}}{2a}\Rightarrow\frac{-4+6}{2\cdot1}=\frac{2}{2}=\boxed1[/tex]
2)
[tex]-5x-4x^2=0 \ \ /\cdot(-1)\\\\4x^2+5x=0\\\\4x(x+1,25)=0\\\\4x=0\Rightarrow\boxed{x=0}\\\\x+1,25=0\Rightarrow\boxed{x=-1,25}[/tex]
