Rút gọn biểu thức \(A=\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot\frac{24}{25}\cdot...\cdot\frac{899}{900}\)
Rút gọn biểu thức A=\(\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot\frac{24}{25}\cdot....\cdot\frac{899}{900}\)ta được A=......
(Nhập kết quả dạng phân số tối giản)
~ So sad :( !! ~
\(A=\frac{31}{60}\)
I thinks so ! Sad
Tính tích
M=\(\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot\frac{24}{25}\cdot...\cdot\frac{99}{100}\)
\(M=\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.\frac{24}{25}...\frac{99}{100}\)
\(=\frac{3.8.15.24....99}{4.9.16.25....100}\)
\(=\frac{1.3.2.4.3.5.4.6....9.11}{2.2.3.3.4.4.5.5....10.10}\)
\(=\frac{1.2.3.4....9}{2.3.4.5....10}.\frac{3.4.5.6....11}{2.3.4.5....10}\)
\(=\frac{1}{10}.\frac{11}{2}\)
\(=\frac{11}{20}\)
Study well ! >_<
\(M=\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.\frac{24}{25}...\frac{99}{100}\)
\(\Rightarrow M=\frac{1.3}{2.2}.\frac{2.4}{3.3}.\frac{3.5}{4.4}.\frac{4.6}{5.5}...\frac{9.11}{10.10}\)
\(\Rightarrow M=\frac{1.3.2.4.3.5...9.11}{2.2.3.3.4.4...10.10}\)
\(\Rightarrow M=\frac{\left(1.2.3...9\right)\left(3.4.5...11\right)}{\left(2.3.4...10\right)\left(2.3.4...10\right)}\)
\(\Rightarrow M=\frac{11}{10.2}\)
\(\Rightarrow M=\frac{11}{20}\)
\(M=\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot\frac{24}{25}...\cdot\frac{99}{100}\)
\(=\frac{3.8.15.24...99}{4.9.16.25....100}\)
\(=\frac{1.3.2.4.3.5.4.6....9.11}{2.2.3.3.4.4.5.5....10.10}\)
\(=\frac{1.2.3....9}{2.3.4.5....10}\cdot\frac{3.4.5.6....11}{2.3.4.5....10}\)
\(=\frac{1}{10}\cdot\frac{11}{2}\)
\(=\frac{11}{20}\)
\(B=\frac{8}{9}\cdot\frac{15}{16}\cdot\frac{24}{25}\cdot...\cdot\frac{3599}{3600}\)
B = \(\frac{8}{9}.\frac{15}{16}.\frac{24}{25}...\frac{3599}{3600}\)
= \(\frac{2.4}{3.3}.\frac{3.5}{4.4}.\frac{4.6}{5.5}...\frac{59.61}{60.60}\)
= \(\frac{2.4.3.5.4.6...59.61}{3.3.4.4.5.5...60.60}\)
= \(\frac{2.3....59}{3.4...60}.\frac{4.5...61}{3.4...60}\)
= \(\frac{2}{60}.\frac{61}{3}\)= \(\frac{61}{90}\)
Chúc bạn học tốt!
\(\frac{3}{4}\cdot\frac{9}{8}\cdot\frac{15}{16}\cdot\frac{24}{25}\cdot\frac{35}{36}\cdot\frac{48}{49}\)
Mong các bạn giúp đỡ.
Hình như sai đề bài bạn nhé! Đề bài đúng như dưới nhé!
\(\frac{3}{4}\).\(\frac{8}{9}.\frac{15}{16}.\frac{24}{25}.\frac{35}{36}.\frac{48}{49}\)
= \(\frac{1.3}{2.2}.\frac{2.4}{3.3}.\frac{3.5}{4.4}.\frac{4.6}{5.5}.\frac{5.7}{6.6}.\frac{6.8}{7.7}\)
= \(\left(\frac{1.2.3.4.5.6}{2.3.4.5.6.7}\right).\left(\frac{3.4.5.6.7.8}{2.3.4.5.6.7}\right)\)
= \(\frac{1}{7}.\frac{8}{2}\)
= \(\frac{1}{7}.4=\frac{4}{7}\)
Hà ơi cho mình hỏi bạn lấy đề ở đâu vậy. Mình lấy đề ở trong sách NĂNG LỰC TỰ HỌC TOÁN 6 đấy.
\(\frac{3}{2^2}\cdot\frac{8}{32}\cdot\frac{15}{4^2}\cdot......\cdot\frac{899}{30^2}\)
C=\(\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot\cdot\cdot\frac{80}{81}\cdot\frac{99}{100}\)
\(C=\frac{3.8.15....80.99}{4.9.16.81.100}\)
\(=\frac{1.3.2.4.3.5...8.10.9.11}{2.2.3.3.4.4...9.9.10.10}\)
\(=\frac{\left(1.2.3....9\right).\left(3.4.5...10.11\right)}{\left(2.3.4.5...10\right).\left(2.3.4...10\right)}\)
\(=\frac{11}{10}\)
trả lời
c=\(\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot....\cdot\frac{99}{100}\)
C=\(\frac{3.8.15....99}{4.9.16.100}\)
C=\(\frac{1.3.2.4.3.5.....9.11}{2.2.3.3.4.4....10.10}\)
C=\(\frac{\left(1.2.....9\right)}{2.3....10}.\left(\frac{3.4....11}{2.3...10}\right)\)
C=\(\frac{1}{10}\cdot\frac{11}{2}=\frac{11}{20}\)
làm ẩu quá
đoạn cuối \(=\frac{11}{20}\)nha sorry
bn lê trung hiếu làm đúng rồi !
Tính A
A=\(\frac{3}{2^2}\cdot\frac{8}{3^2}\cdot\frac{15}{4^2}\cdot...\cdot\frac{899}{30^2}\)
\(\frac{3}{4}\cdot\frac{8}{9}\cdot\frac{15}{16}\cdot\cdot\cdot\cdot\frac{9999}{10000}\)=?
\(\frac{3}{4}.\frac{8}{9}.\frac{15}{16}...\frac{9999}{10000}=\frac{1.3}{2.2}.\frac{2.4}{3.3}.\frac{3.5}{4.4}....\frac{99.101}{100.100}\)
=\(\frac{1.3.2.4.3.5....999.101}{2.2.3.3.4.4....100.100}=\frac{1.101}{2.100}=\frac{101}{200}\)
\(B=\frac{8}{9}\cdot\frac{15}{16}\cdot\frac{24}{25}\cdot...\cdot\frac{3599}{3600}\)
Nhờ các bạn tính giùm.
\(B=\frac{8}{9}^.\frac{15}{16}^.\frac{24}{25}^........^.\frac{3599}{3600}\)
\(B=\frac{2.4}{3.3}.\frac{3.5}{4.4}.\frac{4.6}{5.5}.....\frac{59.61}{60.60}\)
B = \(\left(\frac{2.3.4.....59}{3.4.5.....60}\right).\left(\frac{4.5.6.....61}{3.4.5.....60}\right)\)
\(B=\frac{2}{60}.\frac{61}{3}\)
B = \(\frac{61}{90}\)
B= \(\frac{8}{9}.\frac{15}{16}.\frac{24}{25}...\frac{3599}{3600}\)
B= \(\frac{2.4}{3.3}.\frac{3.5}{4.4}.\frac{4.6}{5.5}...\frac{59.61}{60.60}\)
B=\(\frac{2.61}{3.60}\)
B= \(\frac{61}{90}\)