Question

Alguém poderia me explicar como resolver essa equação de 1°grau

x elevado a 2 -5×+4=0

Answer 1

$\mathtt{x^2-5x+4=0} \\ \\ \mathtt{a = 1} \\ \mathtt{b = -5} \\ \mathtt{c = 4} \\ \\ \mathtt{\Delta = b^2-4~.~a~.~c} \\ \mathtt{\Delta = (-5)^2-4~.~1~.~4} \\ \mathtt{\Delta = 25 -16} \\ \mathtt{\Delta = 9} \\ \\ \mathtt{\dfrac{-b+- \sqrt\Delta}{2~.~a} = \dfrac{-(-5)+-\sqrt9}{2~.~1} = \dfrac{5 +-~3}{2}} \\ \\ \\ \mathtt{x' = \dfrac{5 + 3}{2}~~ = ~~\dfrac{8}{2}~~ = ~~\boxed4} \\ \\ \\ \mathtt{x'' = \dfrac{5 -3}{2}~~=~~\dfrac{2}{2}~~=~~\boxed1} \\ \\ \\ \boxed{\boxed{\mathtt{Resposta: S:(1~~,~~4)}}}$