Question

x la a doua +9×+20 cat este​

Answer 1

Răspuns:

x²+9x+20=0

∆=b²-4ac

∆=81-4×20

∆=81-80

∆=1

X1/2=-b±√∆ supra 2a

=-9±1 supra 2

X1=-9+1 supra 2

=-8 supra 2

=-4

X2=-9-1 supra 2

=-10 supra 2

=-5