Question

x2-5x+4=0 (x2 ma refer la x la puterea a 2-a) (Este ecuatia de gradul 2)

Answer 1

 

$\displaystyle\bf\\x^2-5x+4=0\\\\x_{12}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}=\frac{5\pm\sqrt{25-16}}{2}=\frac{5\pm\sqrt{9}}{2}=\frac{5\pm3}{2}\\\\x_1=\frac{5-3}{2}=\frac{2}{2}=\boxed{\bf1}\\\\x_2\frac{5+3}{2}=\frac{8}{2}=\boxed{\bf4}$