Question

va rog faceți exercițiul a dau coiana ​

Answer 1

 

$\displaystyle\bf\\Metoda~1~de~rezolvare:\\\\x^2-10x+9=0\\x^2-x-9x+9=0\\x(x-1)-9(x-1)=0\\(x-1)(x-9)=0\\x-1=0\implies \boxed{\bf x_1=1}\\x-9=0\implies \boxed{\bf x_2=9}\\\\Metoda~2~de~rezolvare:\\\\x^2-10x+9=0\\\\x_{12}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\\\\x_{12}=\frac{10\pm\sqrt{100-36}}{2}\\\\x_{12}=\frac{10\pm\sqrt{64}}{2}\\\\x_{12}=\frac{10\pm8}{2}\\\\x_{12}=5\pm4\\\\x_1=5-4=1\\\\x_2=5+4=9\\\\\boxed{\bf x_1=1~~si~~x_2=9}$