Question

Soluțiile ecuației x la a 2a +2x - 1 = 0

Answer 1

$\displaystyle x^2+2x-1=0 \\ a=1,b=2,c=-1 \\ \Delta=b^2-4ac=2^2-4 \cdot 1 \cdot (-1)=4+4=8 \\ x_1= \frac{-2+ \sqrt{8} }{2 \cdot 1} = \frac{-2+2 \sqrt{2} }{2} = \frac{\not2(-1+ \sqrt{2} )}{\not2} =-1+ \sqrt{2} \\ x_2= \frac{-2- \sqrt{8} }{2 \cdot 1} = \frac{-2-2 \sqrt{2} }{2} = \frac{\not2(-1- \sqrt{2} )}{\not2} =-1- \sqrt{2}$