2/5<3/5<2/3

lm bài nào v

8)x²+4x+5x+20=(x²+4x)+(5x+20)=x.(x+4)+5.(x+4)=(x+5).(x+4)

9)x²-2x-5x+10=(x²-2x)-(5x-10)=x.(x-2)-5.(x-2)=(x-5).(x-2)

10)x²+3x+6x+18=(x²+3x)+(6x+18)=x.(x+3)+6.(x+3)=(x+6).(x+3)

njhanh nhỉ

1)(x²+2xy+y²)-4=(x+y)²-4=(x+y-2).(x+y+2)

2)3xy²-12xy+12x=3x.(y²-4y+4)=3x.(y-2)²