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...
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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
Ta có (x,y)=15 => \(\hept{\begin{cases}x=15.x^,\\y=15.y^,\end{cases}}\)
Ta có x.y=540
(=) \(15.x^,.15.y^,=540\)
(=) \(225.x^,.y^,=540\)
(=) \(x^,.y^,=2,4\)
Đến đây cậu làm tiếp nha
\(\text{Ta có : }\) \(\left(x,y\right)=15\text{ }\Rightarrow\text{ }\hept{\begin{cases}x=15\cdot x\\y=15\cdot y\end{cases}}\)
\(x\cdot y=540\)
\(\Rightarrow\text{ }15\cdot x\cdot15\cdot y=540\)
\(\Rightarrow\text{ }15\cdot\left(x+y\right)=540\)
\(\Rightarrow\text{ }\left(x+y\right)=540\text{ : }15\)
\(\Rightarrow\text{ }x+y=36\)
\(\text{Cậu tự làm tiếp nha ! }\)