Tim 1 so co 4 chu so abca biet abca = (5c +a)2
tim so co 4 chu so abca biet abca =(5c+1)2 giai chi tiet
1) hai mu2+2 mu3 +2mu10 .......+2mu100
2) tim chu so tan cungcua so[2mu 2013]o tren co mu 2
tim 1 so tu nhien co 4 chu so sao cho khi nhan so do voi 4 ta duoc 1 so co 6 chu so , so nay bang so co duoc khi ta viet them vao ben trai so phai tim 2 chu so va 2
Cau1 Tim cac chu so x, y sao cho so co 4 chu so 4x7 y chua het cho tat ca cac so 2,3,5
Cau 2 :Tim x la so tu nhien be nhat sao cho x > 10,35
Cau 3 : Tim x la so tu nhien lon nhat sao cho x < 8,2
tim so nguyen x sao cho 2^5-x la so nguyen am lon nhat co 3 chu so
tim so nguyen x sao cho -19-x la so nguyen am lon nhat co 4 chu so tm x
tim so nguyen x sao cho-19-x la so nguyen am lon nhat co 4 chu so
Bai 1: a)Tim so tu nhien a biet 1960va2002 chia cho a cung co so du la 28
b)Tim 2 sop tu nhien a va b , biet :BCNN(a,b)=300;UCLN(a,b)=15 va a+15=b
Bai 2:a)Tong sau la binh phuong so nao ?
S=1+3+5+7+...+199
b) Cho so ab va so ababab
1)chung to ababab la boi cua ab
2)So 3 va 10101 co phai la uoc cua ababab khong , vi sao?
Bai 3
a)Hay viet them dang sau so 664 ba chu so de nhan duoc sdo co 6 chu so chia het cho 5,9,11
b)Tim so nguyen x thuoc Z biet rang :
(x^2-1)(x^2-4)<0
Bai 4 :tim so nguyen x va y biet: xy-x+2y=3