Question

x²+4x-5=0
rog sa fiu ajutat

Answer 1

Răspuns:

1 si -5

Explicație pas cu pas:

$\displaystyle x^2+4x-5=0$

Stim ca:

a=1

b=4

c=-5

Calculam delta

$\Delta=b^2-4ac \\ \Delta=4^2-4\cdot1\cdot(-5) \\ \Delta=36$

Acum aflam solutiile

$\displaystyle \boxed{X_{1,2}=\frac{-b\pm\sqrt{\Delta} }{2a} }$

$\displaystyle X1=\frac{-b-\sqrt{\Delta} }{2a} = \frac{-4-6}{2} =\frac{-10}{2}=-5 \\\\ X2=\frac{-b+\sqrt{\Delta} }{2a} = \frac{-4+6}{2}=\frac{2}{2}=1$