tim cac so nho hon 2000 lon hon 1000 chia het cho 2 du 1,chia 3 du 2, chia4 du 3, chia 5 du 4. chia 6 du 5,7 du 6 trinh bay ho to voi>->->->->-thaks
tim cac so nho hon 2000 lon hon 1000 chia het cho 2 du 1,chia 3 du 2, chia4 du 3, chia 5 du 4. chia 6 du 5,7 du 6 trinh bay ho to voi>->->->->-thaks
Gọi số cần tìm là a
Ta có:a+1chia hết cho 2,3,4,5,6,7
Vậy a+1 [TEX]\epsilon [/TEX] BC(2,3,4,5,6,7)
Mà BCNN(2,3,4,5,6,7)=2[TEX]^2[/TEX].3.5.7=420
Vậy a+1= {420,840,1260...}
Nhưng 1000<a<2000
\Rightarrow1001<a+1<2001
a+1={420,840,1260,1680,}
a={419,839,1259,1679}.