Tính bằng máy tính cầm tay

mình cần tính nhanh cơ hoặc tính ra đày đủ đó

a)4.-1/8+1/2=-4/8+1/2

b)1/36.36+(0,6^1)^2/(0,2^3)^2

=1+0,36/0,000064

=1+5625

=5626

\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)....\left(1-\frac{1}{2009}\right)\)

=\(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{2008}{2009}\)

=\(\frac{1}{2009}\)

a) \(\frac{2^5\cdot2^{12}\cdot2^6}{2^{24}}=\frac{2^{23}}{2^{24}}=\frac{1}{2}\)

Các phần kia tương tự, à bạn đăng 1 2 câu hỏi 1 lần thôi, đăng nhiều quá ko ai trả lời đâu

@-@

Thế à ! Vậy bạn hãy nhấp vào https://h.vn/hoi-dap/question/646555.html?pos=1792187 mà xem

  (1-1/2)(1-1/3)(1-1/4)...(1-1/2009)

=1/2*2/3*3/4*...*2008/2009

=\(\frac{1\cdot2\cdot3\cdot...\cdot2008}{2\cdot3\cdot4\cdot...\cdot2009}\)

=1/2009

=1/2x2/3x3/4x...../2008/2009

=1/2009

d) \(\dfrac{8^4.3^6}{2^7.65}=\dfrac{\left(2^3\right)^4.3^6}{2^7.65}=\dfrac{2^{12}.3^6}{2^7.65}=\dfrac{2^7.2^5.3^6}{2^7.65}=\dfrac{2^5.3^6}{65}=\dfrac{23328}{65}\)

c) \(\left(\dfrac{3}{5}-\dfrac{3}{4}\right).\left(\dfrac{2}{6}-\dfrac{1}{5}\right)^2=\dfrac{3.4-3.5}{4.5}.\left(\dfrac{2.5-1.6}{6.5}\right)^2\\ =\dfrac{-3}{20}.\left(\dfrac{2}{15}\right)^2=\dfrac{-3}{20}.\dfrac{4}{225}\\ =\dfrac{-3}{4.5}.\dfrac{4}{75.3}=\dfrac{-1}{375}\)

a) \(\dfrac{2^5.8^4.4^3}{16^6}=\dfrac{2^5.\left(2^3\right)^4.\left(2^2\right)^3}{\left(2^4\right)^6}=\dfrac{2^5.2^{12}.2^6}{2^{24}}=\dfrac{2^{23}}{2^{24}}=\dfrac{1}{2}\)

A=\(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{2014}{2015}.\frac{2015}{2016}\)

A=\(\frac{1.2.3.4...2015}{2.3.4...2016}=\frac{1}{2016}\)

Hok tốt

A = \(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{2015}\right).\left(1-\frac{1}{2016}\right)\)

= \(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{2014}{2015}.\frac{2015}{2016}\)

= \(\frac{1}{2016}\)

Vậy ...

\(A=\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)......\left(1-\frac{1}{2015}\right)\left(1-\frac{1}{2016}\right)\)

\(\Rightarrow A=\frac{1.2.3.4....2015}{2.3.4....2016}\)

\(\Rightarrow A=\frac{1}{2016}\)

#hok tốt

(1-1/3).(1-1/5).(1-1/7).(1-1/9).(1-1/11).(1-1/13).(1-1/2).(1-1/4).(1-1/6).(1-1/8).(1-1/10)

=2/3.4/5.6/7.8/9.10/11.12/13.1/2.3/4.5/6.7/8.9/10

=8/15.48/63.120/143.3/8.35/48.9/10

=384/945.360/1144.315/480

=138240/1081080.315/480

=43545600/518918400=84/1001

khó quá

\(\left(1-\frac{1}{3}\right)\left(1-\frac{1}{5}\right)\left(1-\frac{1}{7}\right)\)    \(\left(1-\frac{1}{11}\right)\)\(\left(1-\frac{1}{13}\right)\left(1-\frac{1}{2}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{6}\right)\)
 \(=1.\left(\frac{1}{3}-\frac{1}{2}\right).\left(\frac{1}{5}-\frac{1}{4}\right).\left(\frac{1}{7}-\frac{1}{6}\right)\)\(.\left(\frac{1}{11}-\frac{1}{10}\right).\frac{1}{13}\)
  \(=1.1.1.1.1.\frac{1}{13}\)
   \(=\frac{1}{13}\)
Cái này là chỉ do mình nghĩ thôi, ko biết đúng ko nữa
Có sai cko mình sorry nha!
Tk và kb hộ mình  với! thanks 

=> 1/2.2/3.3/4...x/(x+1)=1/2009

=>  1/(x+1)=1/2009

=>   x+1=2009

=>   x=2008

Mik nhanh nhất mik nha

=> 1/2 . 2/3 . 3/4 .... x/x+1 = 1/2009

<=> (1.2.3...x) / [2.3...x.(x+1)] = 1/2009

<=> 1/ (x+1) = 1/2009

=> x+1=2009 => x=2008

tính gì