tim x dua vao quan he uoc boi:tim so tu nhien x sao cho x-1 la uoc cua 12tim so tu nhien x sao cho 2x+1 la uoc cua 28tim so tu nhien x sao cho x+15 la boi cua x+3tim cac so nguyen x,y sao cho (x+1)(y-2)=3tim so nguyen x sao cho(x+2).(y-1)=2tim so nguyen to x vua la uoc cua 275 vua la uoc cua 180tim so nguyen to x,y biet x+y=12 va UCLL (x:y)=5tim so tu nhien x,y biet x+y=32 va UCLL (x:y)=8tim so tu nhien x biet x chia het cho10; xchia het cho12; x chia het cho15 va 100<x<150tim so x nho nhat khac 0b...
Đọc tiếp
tim x dua vao quan he uoc boi:
tim so tu nhien x sao cho x-1 la uoc cua 12
tim so tu nhien x sao cho 2x+1 la uoc cua 28
tim so tu nhien x sao cho x+15 la boi cua x+3
tim cac so nguyen x,y sao cho (x+1)(y-2)=3
tim so nguyen x sao cho(x+2).(y-1)=2
tim so nguyen to x vua la uoc cua 275 vua la uoc cua 180
tim so nguyen to x,y biet x+y=12 va UCLL (x:y)=5
tim so tu nhien x,y biet x+y=32 va UCLL (x:y)=8
tim so tu nhien x biet x chia het cho10; xchia het cho12; x chia het cho15 va 100<x<150
tim so x nho nhat khac 0b biet x chia het cho 24 va 30
40 chia het cho x . 56 chia het cho x va x>6
\(2009-|x-2009|=x\)
Nếu \(x\ge2009\Rightarrow2009-x+2009=x\)
\(\Rightarrow2.2009-2x\)
\(\Rightarrow x=2009\)
Nếu \(x< 2009\Rightarrow2009-2009+x=x\)
\(\Rightarrow0=0\)
Vậy với \(\forall x< 2009\)thì thỏa mãn
vậy với \(x\le2009\)thì \(2009-|x-2009|=x\)
hoặc cách này nha:
\(2009-|x-2009|=x\)
\(\Rightarrow2009-x=|x-2009|\)
\(\Rightarrow|x-2009|=-\left(x-2009\right)\)
\(\Rightarrow x\le2009\)