Các câu hỏi tương tự
Tính nhanh: \(\left(\frac{1}{49}-\frac{1}{2^2}\right)\times\left(\frac{1}{49}-\frac{1}{3^2}\right)\times...\times\left(\frac{1}{49}-\frac{1}{40^2}\right)\)
Tính nhanh:
\(\left(\frac{1}{49}-\frac{1}{2^2}\right)\left(\frac{1}{49}-\frac{1}{3^2}\right)...\left(\frac{1}{49}-\frac{1}{40^2}\right)\)
Help me!!!
a, Cho A= 1/99 + 2/98 + 3/47 + .......... + 98/2 + 99/1
B= 1/2 + 1/3 + 1/4 + ..........+ 1/99 + 1/100
Tính B/A
b, Cho A= 1/49 + 2/48 + 3/47 +.......+ 48/2 +49/1
B= 1 + 2/3 + 2/4 +......+ 2/49 + 2/50
Tính A/B
\(A=\frac{\frac{1}{1}+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{49}+\frac{1}{50}}{\frac{100}{1}+\frac{49}{2}+...+\frac{2}{49}+\frac{1}{50}}\)= ?
Tinh nhanh
(\(\frac{1}{49}\)-\(\frac{1}{2^2}\)) . ( \(\frac{1}{49}\) - \(\frac{1}{3^2}\))........ ( \(\frac{1}{49}\) -\(\frac{1}{40^2}\))
1/50-1/50*49-1/49*48-...-1/2*1
e, \(\frac{49}{1}+\frac{48}{2}+\frac{47}{3}+.......+\frac{2}{48}+\frac{1}{49}=50.\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.......+\frac{1}{50}\right)\)
8 tháng 6 2015 lúc 8:19
\(\sqrt{1+2+3+4+5+...+48+49+50+49+48+...+2+1}\)= ?
D=(4/49)^2*(-49/16)*(-1)^10/(4/25)^2*(-25/144)^2:(-49/144)^2