Question

rezolvati ecuatia 2+x-x²=0

Answer 1

-x^2+x+2 = 0
delta = b^2-4ac = 1+8 = 9
x1 = (-b+Vdelta)/2a = (-1+3)/-2 = 2/-2= -1
x2 = (-b-Vdelta)/2a = (-1-3)/-2 = -4/-2 = 2 
x apartine lui {-1,2}

Answer 2

$\displaystyle 2+x-x^2=0 \\ \text{Rearanjam} \\\\ -x^2+x+2=0/(-1) \\ x^2-x-2=0 \\ \Delta=b^2-4ac \\ \Delta=(1)^2-4\cdot1\cdot(-2)\\ \Delta=1+8=9 \\ \\ X_{1,2}= \frac{-b \pm \sqrt{\Delta} }{2a} \\ \\ X_1= \frac{1+3}{2} =2 \\ \\ X_2= \frac{1-3}{2} =-1 \\ \\ \text{Asadar, solutiile sunt -1 si 2}$