Question

Tìm x biết

x²+5x-6=0

Giúp mình nha

Answer 1

x^2-5x+6=0
<=>x^2-2x-3x+6=0
<=>(x^2-2x)-(3x-6)=0
<=>x(x-2)-3(x-2)=0
<=>(x-2)(x-3)=0
<=>x-2=0 hoac x-3=0
<=>x=2 hoac x=3

Answer 2

x² - 5x + 6 = 0
⇔ x² - 2x - 3x + 6 = 0
⇔ x(x - 2) - 3(x - 2) = 0
⇔ (x - 2)(x - 3) = 0
⇒S = {2 ; 3}.