Question

Rezolvati ecuatiile:4x²-4x=8

Answer 1

Observam forma ecuatiei de gradul ll
ax²+bx+c=0
rezolvam:

4x²-4x=8
4x²-4x-8=0
4(x²-x-2)=0
x²-x-2=0
a=1
b=-1
c=-2
∆=b²-4ac=(-1)²-4*1*(-2)=1+8=9

x1=(-b+√∆)/2a=(-(-1)+√9)/2*1=(1+3)/2=4/2=2

x2=(-b-√∆)/2a=(-(-1)-√9)/2*1=(1-3)/2=-2/2=-1

S={-1;2}