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
Bai 1: Tim x va y
a) ( x+ 5) .( x-3) = 15
b)( 2x -1).(y + 2) =24
c)x.y+y+x =30
d) 3x.y+2x +2y=0
Bài 2: tìm các số nguyên tố P
a) de P +2;P+94 cung la so nguyen to
b) de P+6;P+8;P+12;P+14 cung la so nguyen to
Cau 1: Co tat ca bao nhieu so co 3 chu so ma trong moi so co duy nhat 1 chu so 5.
Cau 2: Biet rang 3n+1 va 5n+4 (n thuoc N) la hai so khong nguyen to cung nhau. Khi do UCLN cua 3n+1 va 5n+4 la bao nhieu.
Cau 3: Tim cap (x;y) nguyen am thoa man:xy+3x+2y+6=0 va lxl+lyl=5.
tim cac so nguyen to x va y sao cho cac so 5x+y va xy+13 cung la so nguyen to
giai nhanh giup minh nha mai minh phai nop roi
tim so nguyen to p sao cho:
a,p+2 va p+4 la so nguyen to
b,p+2 va p+6 va p+8 la so nguyen to
c,p+10 va p+14 la so nguyen to
1) Tim so nguyen to P de co:
a) P+10 va P+14 deu la so nguyen to
b) P+2 ;P+6 va P+8 deu la so nguyen to
Tim so nguyen to x va y biet x^2-x+993*y=2006
tim so nguyen to x va y sao cho x^2 + 45 = y^2
Tim n thuoc N biet so n co 30 uoc va khi phan tich thanh thua so nguyen to thi co dang n = 2^x × 3^y biet x+y =8