Các câu hỏi tương tự
Tính nhanh nếu có thể:
a)
\(\frac{1}{3}+\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+\frac{1}{99}+\frac{1}{143}+\frac{1}{195}\)
b)
\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}+\frac{1}{55}+\frac{1}{66}\)
Tính nhanh
\(A=1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)\(\frac{1}{45}\)
Nhanh tk !!
1+\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)
\(\frac{1}{45}-\frac{1}{36}-\frac{1}{28}-\frac{1}{21}-\frac{1}{15}-\frac{1}{10}-\frac{1}{6}-\frac{1}{3}-1\)
\(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}=m\text{ấ}y\)
tìm x biết \(\frac{x}{6}+\frac{x}{10}+\frac{x}{15}+\frac{x}{21}+\frac{x}{28}+\frac{x}{36}+\frac{x}{45}+\frac{x}{55}+\frac{x}{66}+\frac{x}{78}+\frac{x}{78}=\frac{220}{39}\)
1/Tính:
A= \(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}\)
B= \(\frac{5}{1.4.7}+\frac{5}{4.7.10}+\frac{5}{7.10.13}+...+\frac{5}{94.97.100}\)
Các bạn vui lòng giải đầy đủ giúp mình nhé! Cảm ơn rất nhiều!
Tính hợp lý:
\(\frac{16}{9}-\frac{1}{36}-\frac{1}{28}-\frac{1}{21}-\frac{1}{15}-\frac{1}{10}-\frac{1}{6}-\frac{1}{3}-1\)
a, \(\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+...+\frac{1}{306}\)
b, \(\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+...+\frac{1}{120}\)
Tính tổng các phân số trên