Question

Tìm x biết :

a) x( x - 2 ) - 5x + 10 = 0

b) ( x + 3 )² - x² - 9 = 0

c) ( x + 2 )² + ( x - 3 )² - 2( x - 1 )(x + 1 ) = 9

Answer 1

b)(x+3)\(^2\)-x\(^2\)=9

(x+3-x)(x+3+x)=9

3(2x+3)=9

2x+3=3

2x=0

x=0

c)\(x^2+4x+4+x^2-6x+9-2x^2+2=9\)

-2x+15=9

-2x=-6

x=3

Answer 2

a) x(x-2) - 5x + 10 = 0

x(x - 2) - 5(x - 2)=0

(x - 2)(x - 5)=0

=> x=2 ; x=5

Answer 3

                                                                      GIẢI

<=> x(x-2)-5(x-2)=0

<=>(x-2)(x-5)=0

<=>x-2=0

      x-5=0

<=>x=2

      x=5