Mày hay nhờ mai tao méc thầy

tự làm đi

\(\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot\cdot\cdot\cdot\frac{624}{625}\)

\(=\frac{1.3}{2.2}\cdot\frac{2.4}{3.3}\cdot\frac{3.5}{4.4}\cdot\cdot\cdot\cdot\frac{24.26}{25.25}\)

\(=\frac{1.2.3....24}{2.3.4....25}\cdot\frac{3.4.5....26}{2.3.4....25}\)

\(=\frac{1}{25}\cdot\frac{26}{2}=\frac{26}{50}=\frac{13}{25}\)

\(\left(1+\frac{1}{3}\right)\cdot\left(1+\frac{1}{8}\right)\cdot\left(1+\frac{1}{15}\right)\cdot\cdot\cdot\cdot\left(1+\frac{1}{9999}\right)\)

\(=\frac{4}{3}\cdot\frac{9}{8}\cdot\frac{16}{15}\cdot\cdot\cdot\cdot\frac{10000}{9999}\)

\(=\frac{2.2}{1.3}\cdot\frac{3.3}{2.4}\cdot\frac{4.4}{3.5}\cdot\cdot\cdot\cdot\frac{100.100}{99.101}\)

\(=\frac{2.3.4...100}{1.2.3...99}\cdot\frac{2.3.4...100}{3.4.5...101}\)

\(=\frac{100}{1}\cdot\frac{2}{101}=\frac{200}{101}\)

3/4.8/9.15/16.....624/625

=(1.3)/(2.2).(2.4)/(3.3).(3.5)/(4.4)...(24.26)/(25.25)

=(1.2.3....24).(3.4.5....26)/(2.3.4...25).(2.3.4...25)

=26/25.2

=26/50

=13/25

- Đặt \(A=\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.....\frac{624}{625}\)

- Ta có: \(A=\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.....\frac{624}{625}\)

\(\Leftrightarrow A=\frac{1.3}{2.2}.\frac{2.4}{3.3}.\frac{3.5}{4.4}.....\frac{24.26}{25.25}\)

\(\Leftrightarrow A=\frac{1.2.3.....24}{2.3.4.....25}.\frac{3.4.5.....26}{2.3.4.....25}\)

\(\Leftrightarrow A=\frac{1}{25}.\frac{26}{2}\)

\(\Leftrightarrow A=\frac{1}{25}.13=\frac{13}{25}\)

Vậy \(A=\frac{13}{25}\)

T = \(\frac{3}{4}.\frac{8}{9}.\frac{15}{16}....\frac{624}{625}\)

T = \(\frac{1.3.2.4.3.5.....24.26}{2.2.3.3.4.4.....25.25}\)

T = \(\frac{\left(1.2.3.....24\right)\left(3.4.5.....26\right)}{\left(2.3.4.....25\right)\left(2.3.4.....25\right)}\)

T = \(\frac{26}{25.2}\)

T = \(\frac{13}{25}\)

\(\dfrac{3}{4}.\dfrac{8}{9}.\dfrac{15}{16}....\dfrac{624}{625}\)

\(=\dfrac{3.8.15...624}{4.9.16...625}\)

\(=\dfrac{\left(1.3\right)\left(2.4\right)\left(3.5\right)...\left(24.26\right)}{\left(2.2\right)\left(3.3\right)\left(4.4\right)...\left(25.25\right)}\)

\(=\dfrac{\left(1.2.3...24\right)\left(3.4.5...26\right)}{\left(2.3.4...25\right).\left(2.3.4...25\right)}\)

\(=\dfrac{1.26}{25.2}\)

\(=\dfrac{13}{25}\)

\(\dfrac{3}{4}\cdot\dfrac{8}{9}\cdot\dfrac{15}{16}\cdot\cdot\cdot\dfrac{624}{625}\)

\(=\dfrac{1.3}{2.2}\cdot\dfrac{2.4}{3.3}\cdot\dfrac{3.5}{4.4}\cdot\cdot\cdot\dfrac{24.26}{25.25}\)

\(=\dfrac{1.2.3....24}{2.3.4....25}\cdot\dfrac{3.4.5....26}{2.3.4...25}\)

\(=\dfrac{1}{25}\cdot\dfrac{26}{2}=\dfrac{13}{25}\)

\(\dfrac{3}{4}\cdot\dfrac{8}{9}\cdot\dfrac{15}{16}\cdot....\cdot\dfrac{624}{625}=\dfrac{3}{2\cdot2}\cdot\dfrac{2\cdot4}{3\cdot3}\cdot\dfrac{3\cdot5}{4\cdot4}\cdot...\cdot\dfrac{9\cdot11}{10\cdot10}=\dfrac{11}{2\cdot10}=\dfrac{11}{20}\)

375x376=141000

624x625=390000

13x81x215=226395

375.376=3.125.47.8=141.1000=141000

624.625=16.39.625=10000.39=39000

13.81.215=226395

Tính nhanh:

 a) 2003*5+2003+2003*4

=2003x(5+1+4)

=2003x10

=20030

giúp mk câu b với !!!

a) 2003x5+2003+2003x4

= 10015+2003+8012

= 20030

b) 736x625-254/624x736+482

= 460000-11684/39+482

= 459700.4103+482

= 460182.4103