C = \(\left(1-\frac{1}{3}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{10}\right)...\left(1-\frac{1}{210}\right)=\frac{2}{3}.\frac{5}{6}.\frac{9}{10}...\frac{209}{210}=\frac{4}{6}.\frac{10}{12}.\frac{18}{20}...\frac{418}{420}\)
= \(\frac{2.2}{2.3}.\frac{2.5}{3.4}.\frac{3.6}{4.5}...\frac{19.22}{20.21}=\frac{2.2\left(2.3.4...19\right)\left(5.6...22\right)}{\left(2.3.4..20\right)\left(3.4.5..21\right)}=\frac{4.22}{19.3.4}=\frac{22}{57}\)
Tính giá trị biểu thức: C=(1-1/3)(1-1/6)(1-1/10)(1-1/15)...(1-1/210)
\(C=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{10}\right)\left(1-\frac{1}{15}\right)...\left(1-\frac{1}{210}\right)\)
\(C=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{10}\right)\left(1-\frac{1}{15}\right)...\left(1-\frac{1}{210}\right)\)
Tính nhanh biết \(C=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{10}\right)\left(1-\frac{1}{15}\right)...\left(1-\frac{1}{210}\right)\)
Tính
A= 512 - 512/2 - 512/2^2 - 512/2^3 - ....- 512/210
E= 1 - 1/10 - 1/15 - 1/3 - 1/28 - 1/6 - 1/21
C= 11/1.3 + 47/3.5 + 107/5.7 + 191/7.9 +...+ 971/17.19
Tính giá trị của biểu thức sau
C= \(\left(1-\frac{1}{3}\right)×\left(1-\frac{1}{6}\right)×\left(1-\frac{1}{10}\right)×\left(1-\frac{1}{15}\right)×...×\left(1-\frac{1}{210}\right)\)
Tính giá trị các biểu thức sau: C = (1 – \(\frac{1}{3}\) )(1- \(\frac{1}{6}\) )(1- \(\frac{1}{10}\))(1-\(\frac{1}{15}\))….(1 – \(\frac{1}{210}\))
Tính:
(1-1/3).(1-1/6).(1-1/10)...(1-1/210)
Cho số nguyên n biết:
a/ 1+ 2 + 3 +...+ b = 1275
b/ 2 . (1 + 2 + 3^2 +....+3^10) + 1 = 3^n
c/ 2 + 4 + 6 +...+ 2x = 210
d/ 1 + 3 + 5 +...+ (2x-1) = 225
