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
\(\dfrac{1+2y}{18}=\dfrac{1+4y}{24}\)
khi và chỉ khi: \(\left(1+2y\right).24=\left(1+4y\right).18\) \(\Rightarrow24+48y=18+72y\)\(\Rightarrow72y-48y=24-18\)
\(\Rightarrow24y=6\) \(\Rightarrow y=\dfrac{1}{4}\) Lại có: \(\dfrac{1+4y}{24}=\dfrac{1+6y}{6x}\) \(\Rightarrow\dfrac{1+4\cdot\dfrac{1}{4}}{24}=\dfrac{1+6\cdot\dfrac{1}{4}}{6x}\) \(\Rightarrow\dfrac{1}{12}=\dfrac{\dfrac{5}{2}}{6x}\) \(\Rightarrow6x.1=12\cdot\dfrac{5}{2}\) \(\Rightarrow x=30:6=5\) Vậy x=5;y=\(\dfrac{1}{4}\)