Question

Tìm y biết :\(\left(y^2-1\right)+\left(y-1\right)=0\)

Answer 1

(y²-1)+(y-1)=0

<=>(y-1)(y+1)+(y-1)=0

<=>(y-1)(y+1+1)=0

<=>(y-1)(y+2)=0

<=>y-1=0 hoặc y+2=0

<=>y=1 hoặc y=-2

Answer 2

(y²-1)+(y-1)=0

y²-1+y-1=0

y²+y-2=0

y²-y+2y-2=0

y.(y-1)+2.(t-1)=0

(y-1)(y+2)=0

=>y-1=0 hoặc y+2=0

=>y=1 hoặc y=-2