Chung minh phan so sau toi gian voi moi so tu nhien n
21n+25 phan 14n+7
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) \(\frac{4n+1}{14n+3}\)
cach lam bai : chung to rang moi phan so co dang n+2015/n+2016 ( voi n thuoc N ) deu la phan so toi gian
chung to rang voi moi so nguyen n phan so 3n-5/3-2nla phan so toi gian
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)
Chung to rang:14n+3 va 21n+4 la so nguyen to cung nhau voi n la so tu nhien
cac phan so \(\frac{n+1}{2n+3}\)va\(\frac{2n+1}{2n+3}\)la cac phan so toi gian voi moi so nguyen n khac -1
tim phan so toi gian nho nhat co tu va mau la cac so tu nhien sao cho khi nhan phan so lan luot voi moi so \(\frac{10}{7};\frac{5}{6};\frac{15}{9}\)thi moi tich tim duoc la so tu nhien