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
6x = 4y = 3z
=> x : y : z = 3:4:6
áp dụng tính chất dãy tỉ số bằng nhau ta có
\(\frac{x}{3}=\frac{y}{4}=\frac{z}{6}=\frac{x+y+z}{3+4+6}=\frac{18}{13}\)
=> \(\frac{x}{3}=\frac{18}{13}\Rightarrow x=\frac{54}{13}\)
\(\frac{y}{4}=\frac{18}{13}\Rightarrow y=\frac{72}{13}\)
\(\frac{z}{6}=\frac{18}{13}\Rightarrow z=\frac{108}{13}\)
ta đc \(x=4\)
\(y=6\)
\(z=8\)