12 + X−1 =X  − = −X 1 1 X2X X1 1 1 1−   −   −    =21 0 1  1 1 0 1X X X X − =  −  − = −− = − +  =  ==  = −  =1 (1 ) 1 1 1 2 0X X X X X X XVẬY X=1; X= 0

Bài 3: Giải phương trình: x

²

+ x−1 =1HD: 1

2

+ x−1 =x  − = −x 1 1 x

²

x x1 1 1 1−   −   −    =

2

1 0 1  1 1 0 1x x x x − =  −  − = −− = − +  =  ==  = −  =1 (1 ) 1 1 1 2 0x x x x x x xVậy x=1; x= 0