Răspuns :
x² - 2x = 8
x² - 2x - 8 = 0
x² + 2x - 4x - 8 = 0
x(x+2) - 4(x+2) = 0
(x+2)(x-4) = 0
x + 2 = 0 ⇒ x = -2
x - 4 = 0 ⇒ x = 4
x² - 2x - 8 = 0
x² + 2x - 4x - 8 = 0
x(x+2) - 4(x+2) = 0
(x+2)(x-4) = 0
x + 2 = 0 ⇒ x = -2
x - 4 = 0 ⇒ x = 4
x^2-2x-8=0
delta=b^2-4ac=4+32=36
x1=(-b+√delta)/2a=(2+6)/2=8/2=4
x2=(-b-√delta)/2a=(2-6)/2=(-4/2)=(-2)
delta=b^2-4ac=4+32=36
x1=(-b+√delta)/2a=(2+6)/2=8/2=4
x2=(-b-√delta)/2a=(2-6)/2=(-4/2)=(-2)