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
Đề bài \(\Rightarrow\dfrac{6x}{4}=\dfrac{6y}{9}=\dfrac{6x-6y}{4-9}=\dfrac{6.\left(x-y\right)}{-5}=\dfrac{6.-13}{-5}=\dfrac{78}{5}\Rightarrow\left\{{}\begin{matrix}x=\dfrac{52}{5}\\y=\dfrac{117}{5}\end{matrix}\right.\)
Có :`(3x)/2=(2y)/3` `(1)`
`x-y=-13`
`->x=y-13`
Thay `x=y-13` vào `(1)` , ta có :
`(3(y-13))/2=(2y)/3`
`->9(y-13)=4y`
`->9y-117=4y`
`->5y=117`
`->y=117/5`
`->x=117/5 - 13=52/5`