Gọi \(d\in\left(2n+1;3n+2\right)\)
\(\Rightarrow\hept{\begin{cases}2n+1⋮d\\3n+2⋮d\end{cases}\Rightarrow\hept{\begin{cases}6n+3⋮d\\6n+4⋮d\end{cases}\Rightarrow1⋮}d\Rightarrow d=1}\)
\(\Rightarrowđpcm\)
Chung to rang 3n - 5 phan 3 - 2n la phan so toi gian
chung to rang vs moi so tu nhien n , phan so n^3+2n/n^4+3n^2+1 la toi gian
Chung minh rang moi phan so dang n+1/2n+3 ( n thuoc N ) deu la phan so toi gian.
chung to rang 12n+1 phan 30n+2 la phan so toi gian
chung to rang voi moi so nguyen n phan so 3n-5/3-2nla phan so toi gian
cho phan so p=6n+5/3n+2 (n thuoc N)
chung minh rang phan so p la phan so toi gian
giup minh nhe
chung to rang 12n+1/30n+2 la phan so toi gian
chung to rang moi phan so co dang 2*n+3/3*n+5 la phan so toi gian
Cho n thuoc N, chung to cac phan so sau la toi gian :
a, 2n+1/5n+2
b, 5n+2/3n+1
c, 5n+2/(3n+1).(2n+1)
