a) Đặt \(d=\left(3n-2,4n-3\right)\).
Suy ra \(\hept{\begin{cases}3n-2⋮d\\4n-3⋮d\end{cases}}\Rightarrow4\left(3n-2\right)-3\left(4n-3\right)=1⋮d\Rightarrow d=1\).
Ta có đpcm.
b) Đặt \(d=\left(4n+1,6n+1\right)\).
Suy ra \(\hept{\begin{cases}4n+1⋮d\\6n+1⋮d\end{cases}}\Rightarrow3\left(4n+1\right)-2\left(6n+1\right)=1⋮d\Rightarrow d=1\).
Ta có đpcm.
Cho A=3n-5/n+4. Tim n thuoc Z de A co gia tri nguyen.
Giai day du ho minh nhe! Cam on moi nguoi nhieu!
Giup to bai nay voi : Chung minh voi n thuoc N sao phan so sau la phan so toi gian 4n+1/6n+1
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 voi moi n thuoc * thi cac phan so sau day la phan so toi gian
B)\(\frac{2n-1}{2n-2}\)
c) \(\frac{2n+3}{6n+8}\)\
d) \(\frac{4n+1}{14n+3}\)
tinh tong phan so sau:
1/1.3+1/3.5+1/5.7+...+1/2003.2005
lam day du ho minh nhe! cam on moi nguoi nhieu!
Cau 1: Chung minh rang cac phan so sau la phan so toi gian voi moi so nguyen?
a, 8n + 5 phan 6n + 4 b, n + 1 phan 2n + 3 c, 2n + 3 phan 3n + 5
Cau 2: Tim tat ca cac so tu nhien n de phan so sau la toi gian
a, n + 13 phan n - 2. b, 18n + 3 phan 21n + 7
Ai giai day du va nhanh thi mk se tick cho
Chung minh rang phan so sau toi gian voi moi n thuoc N 2n+1/2n(n+1)
cho A = 3N+2/6N+3
A TIM N DE a LA PHAN SO
b chung to A la phan so toi gian voi moi n thuoc N
chung minh rang moi phan so sau toi gian voi moi so tu nhien n:
a.n+1/2n+3 b.2n+3/4n+8
