a,chung minh rang 3^n+2 -2^n+4 + 3^n+ 2^n chia het cho 30 voi moi so nguyen n
b,mot so chia cho 7 du3,chia cho 23 du 7 . hoi so do chia cho 2737 du bao nhieu
c, cho p la so nguyen to lon hon 3,chung to p^2+2018 la hop so
d,tim cac chu so x,y biet x234y chia het cho 90
lam het ho minh nha minh cam on