Question

Rezolvați ecuațiile:

x pătrat - x + 1 =0

-x pătrat + x + 6=0

6x pătrat-5x=0

4x pătrat -5 =0


Va rog repede!!!! Multumesc!

Answer 1

x^2-x+1=0
delta=b^2-4ac=1-4= -3
x1=(-b+√delta)/2a=(1-√3)/2
x2=(-b-√delta)/2a=(1+√3)/2

-x^2+x+6=0
delta=1+24=25
x1=(-1+5)/-2= 4/-2= -2
x2=(-1-5)/-2= -6/-2= 3

6x^2-5x=0
delta=25-0=25
x1=(5+25)/12=30/12=5/2
x2=(5-25)/12= -20/12= -5/3

4x^2-5=0
delta=0+80=80
x1=(0+4√5)/8=4√5/8=√5/2
x2=(0-4√5)/8= -4√5/8= -√5/2