\(\frac{3}{5^2}+\frac{3}{6^2}+\frac{3}{7^2}+...+\frac{3}{20^2}\)
Làm cụ thể nha!!!
Những câu hỏi liên quan
Tính
\(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{20^2}\)
Làm cụ thể nha các bạn!!!
Ta có: \(\frac{1}{2^2}<\frac{1}{1.2}\)
\(\frac{1}{3^2}<\frac{1}{2.3}\)
\(\frac{1}{4^2}<\frac{1}{3.4}\)
.......................
.....................
\(\frac{1}{20^2}<\frac{1}{19.20}\)
=> \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+....+\frac{1}{20^2}<\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+.....+\frac{1}{19.20}\)
=> \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+....+\frac{1}{20^2}<1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+....+\frac{1}{19}-\frac{1}{20}\)
=> \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+....+\frac{1}{20^2}<1-\frac{1}{20}=\frac{19}{20}<1\)
Đúng 0
Bình luận (0)
Thần Hộ Vệ Của Trái Đất điếc hả TÍNH cơ mà
Đúng 0
Bình luận (0)
Xem thêm câu trả lời
\(20\%x+\frac{2}{5}x=x-4\)
\(\frac{\frac{2}{3}+\frac{2}{7}\cdot\frac{1}{14}}{-1-\frac{3}{7}+\frac{3}{28}}\)
\(\frac{1\cdot2+2\cdot4+3\cdot6+4\cdot8+5\cdot10}{3\cdot4+6\cdot8+9\cdot12+12\cdot16+15\cdot20}\)
giải hội mik mới cách làm lun nha
left(frac{-5}{12}+frac{7}{4}-frac{3}{8}right)-left[4frac{1}{2}-7frac{1}{3}right]-left(frac{1}{4}-frac{5}{2}right)left[2frac{1}{4}-5frac{3}{2}right]-left(frac{3}{10}-1right)-5frac{1}{2}+left(frac{1}{3}-frac{5}{6}right)frac{4}{7}-left(3frac{2}{5}-1frac{1}{2}right)-frac{5}{21}+left[3frac{1}{2}-4frac{2}{3}right]frac{1}{8}-1frac{3}{4}+left(frac{7}{8}-3frac{7}{2}+frac{3}{4}right)-left[frac{7}{4}-frac{5}{8}right]left(frac{3}{5}-2frac{1}{10}+frac{11}{20}right)-left[frac{-3}{4}+1frac{7}{2}right]left[-2fr...
Đọc tiếp
\(\left(\frac{-5}{12}+\frac{7}{4}-\frac{3}{8}\right)-\left[4\frac{1}{2}-7\frac{1}{3}\right]-\left(\frac{1}{4}-\frac{5}{2}\right)\)
\(\left[2\frac{1}{4}-5\frac{3}{2}\right]-\left(\frac{3}{10}-1\right)-5\frac{1}{2}+\left(\frac{1}{3}-\frac{5}{6}\right)\)
\(\frac{4}{7}-\left(3\frac{2}{5}-1\frac{1}{2}\right)-\frac{5}{21}+\left[3\frac{1}{2}-4\frac{2}{3}\right]\)
\(\frac{1}{8}-1\frac{3}{4}+\left(\frac{7}{8}-3\frac{7}{2}+\frac{3}{4}\right)-\left[\frac{7}{4}-\frac{5}{8}\right]\)
\(\left(\frac{3}{5}-2\frac{1}{10}+\frac{11}{20}\right)-\left[\frac{-3}{4}+1\frac{7}{2}\right]\)
\(\left[-2\frac{1}{5}-2\frac{2}{3}\right]-\left(\frac{1}{15}-5\frac{1}{2}\right)+\left[\frac{-1}{6}+\frac{1}{3}\right]\)
\(1\frac{1}{8}-\left(\frac{1}{15}-\frac{1}{2}+\frac{-1}{6}\right)+\left[\frac{5}{4}+\frac{3}{2}\right]\)
\(\frac{5}{6}-\left(1\frac{1}{3}-1\frac{1}{2}\right)+\left[\frac{5}{12}-\frac{3}{4}-\frac{1}{6}\right]\)
\(1\frac{1}{4}-\left(\frac{7}{12}-\frac{2}{3}-1\frac{3}{8}\right)+\left[\frac{5}{24}-2\frac{1}{2}\right]-\frac{1}{6}-\left[\frac{-3}{4}\right]\)
\(-2\frac{1}{5}+2\frac{3}{10}-\left(\frac{6}{20}-\left[\frac{2}{8}-1\frac{1}{2}\right]\right)+\left[\frac{7}{20}-1\frac{1}{4}\right]\)
\(-\left[1\frac{2}{3}-3\frac{1}{2}+\frac{1}{4}\right]+\left(\frac{2}{6}-\frac{5}{12}\right)-\left(\frac{1}{3}-\left[\frac{1}{4}-\frac{1}{3}\right]\right)\)
\(-\frac{4}{5}-\left(1\frac{1}{10}-\frac{7}{10}\right)+\left[\frac{3}{4}-1\frac{1}{5}\right]+1\frac{1}{2}\)
\(\frac{3}{21}-\frac{5}{14}+\left[1\frac{1}{3}-5\frac{1}{2}+\frac{5}{14}\right]-\left(\frac{1}{6}-\frac{3}{7}+\frac{1}{3}\right)\)
\(-1\frac{2}{5}+\left[1\frac{3}{10}-\frac{7}{20}-1\frac{1}{4}\right]-\left(\frac{1}{5}-\left[\frac{3}{4}-1\frac{1}{2}\right]\right)\)
\(2\frac{1}{3}-\left(\frac{1}{2}-2\frac{1}{6}+\frac{3}{4}\right)+\left[\frac{5}{12}-1\frac{1}{3}\right]-\frac{7}{8}+3\frac{1}{2}\)
\(2\frac{1}{4}-1\frac{3}{5}-\left(\frac{9}{20}-\frac{7}{10}\right)+\left[1\frac{3}{5}-2\frac{1}{2}\right]+\frac{3}{4}\)
\(\left[\frac{8}{3}-5\frac{1}{4}+\frac{1}{6}\right]-\frac{7}{4}+\frac{-5}{12}-\left(1-1\frac{1}{2}+\frac{1}{3}\right)\)
\(\left(\frac{1}{4}-\left[1\frac{1}{4}-\frac{7}{10}\right]+\frac{1}{2}\right)-2\frac{1}{5}-1\frac{3}{10}+\left[1-\frac{1}{2}\right]\)
TRÌNH BÀY GIÚP MÌNH NHA
Thực hiện phép tính (Tính hợp lý nếu có thể)g) frac{3}{5}:left(frac{-1}{15}-frac{1}{6}right)+frac{3}{5}:left(frac{-1}{3}-1frac{1}{15}right)h) 10.sqrt{0,01}.sqrt{frac{16}{9}+3sqrt{49}-frac{1}{6}sqrt{4}}i) frac{2^4.2^6}{left(2^5right)^2}-frac{2^5.15^3}{6^3.10^2}k) (2frac{1}{3}+3frac{1}{2}):left(-4frac{1}{6}+3frac{1}{7}right)+7frac{1}{2}n) 4frac{25}{16}+25left(frac{9}{16}:frac{125}{64}right):frac{-27}{8}m) [1,5+2frac{1}{2}-left(2sqrt{2}right)^2]:[4frac{1}{2}-sqrt{1,96}+0,9]o) frac{5}{21}.left(4frac...
Đọc tiếp
Thực hiện phép tính (Tính hợp lý nếu có thể)
g) \(\frac{3}{5}:\left(\frac{-1}{15}-\frac{1}{6}\right)+\frac{3}{5}:\left(\frac{-1}{3}-1\frac{1}{15}\right)\)
h) \(10.\sqrt{0,01}.\sqrt{\frac{16}{9}+3\sqrt{49}-\frac{1}{6}\sqrt{4}}\)
i) \(\frac{2^4.2^6}{\left(2^5\right)^2}-\frac{2^5.15^3}{6^3.10^2}\)
k) \((2\frac{1}{3}+3\frac{1}{2}):\left(-4\frac{1}{6}+3\frac{1}{7}\right)+7\frac{1}{2}\)
n) \(4\frac{25}{16}+25\left(\frac{9}{16}:\frac{125}{64}\right):\frac{-27}{8}\)
m) \([1,5+2\frac{1}{2}-\left(2\sqrt{2}\right)^2]:[4\frac{1}{2}-\sqrt{1,96}+0,9]\)
o) \(\frac{5}{21}.\left(4\frac{1}{5}.7\frac{3}{4}+5\frac{1}{4}.4,2\right)\)
p) \(\left(\frac{2}{5}+\frac{2}{7}-\frac{2}{11}\right):\left(\frac{3}{7}-\frac{3}{11}+\frac{3}{5}\right)\)
Làm nhanh làm đúng mình Tick nha :))
\(a,\frac{-3}{5}\times\frac{4}{7}+\frac{-3}{5}\times\frac{2}{7}+\frac{-3}{5}\)
\(b,\frac{8}{19}\times\frac{5}{11}+\frac{7}{19}\times\frac{8}{11}-\frac{8}{15}\times\frac{1}{11}\)
Trả lời cụ thể nha các bạn !
a) =-3/5 x (4/7 + 2/7 + 1) = -3/5 x 13/7 = -39/35
b) =8/11 x 5/19 + 7/19 x 8/11 - 8/11 x 1/15 = 8/11 x ( 5/19 + 7/19 - 1/15 ) = 8/11 x 161/285 = 1288/3235
**** cho mink nha
Đúng 0
Bình luận (0)
\(a,\frac{-3}{5}.\frac{4}{7}+\frac{-3}{5}.\frac{2}{7}+\frac{-3}{5}\)
= \(\frac{-3}{5}.\left(\frac{4}{7}+\frac{2}{7}+1\right)\)
= \(\frac{-3}{5}.\frac{13}{7}\)
= \(\frac{-39}{35}\)
Đúng 0
Bình luận (0)
a) \(\frac{5}{12}+\frac{5}{20}+\frac{5}{30}+...+\frac{5}{9900}\)
b) \(\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+...+\frac{89}{90}\)
c) \(\frac{7}{6}+\frac{13}{12}+\frac{21}{20}+...+\frac{91}{90}\)
d) \(\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{2}{3}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)
Mấy câu như này tách ra kiểu gì?
\(\frac{5}{12}+\frac{5}{20}+\frac{5}{30}+...+\frac{5}{9900}=\frac{5}{3.4}+\frac{5}{4.5}+\frac{5}{5.6}+...+\frac{5}{99.100}\)
\(5\left(\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+...+\frac{1}{99}-\frac{1}{100}\right)\)
\(5\left(\frac{1}{3}-\frac{1}{100}\right)=\frac{97}{60}\)
\(\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+...+\frac{71}{72}+\frac{89}{90}=1-\frac{1}{6}+1-\frac{1}{12}+1-\frac{1}{20}+...+1-\frac{1}{90}\)
\(=8-\left(\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{90}\right)\)
\(=8-\left(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{9.10}\right)\)
\(=8-\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{9}-\frac{1}{10}\right)\)
\(=8-\left(\frac{1}{2}-\frac{1}{10}\right)=8-\frac{2}{5}=\frac{38}{5}\)
a ) 4frac{5}{9}div(-frac{5}{7})+frac{4}{9}divfrac{left(-5right)}{7}b ) (-frac{3}{5}+frac{4}{9})divfrac{7}{11}+(frac{-2}{5}+frac{5}{9})divfrac{7}{11}c ) frac{6}{7}div(frac{3}{26}-frac{3}{13})+frac{6}{7}div(frac{1}{10}-frac{8}{5})d ) A(2+4+6+........+100)orbr{begin{cases}35end{cases}}div0,7+3(frac{-2}{7})]div(frac{1}{2}+frac{1}{4}+frac{1}{6}+......+frac{1}{100})Giải cụ thể hộ mk vs
Đọc tiếp
a ) 4\(\frac{5}{9}\)\(\div\)\((-\frac{5}{7})\)\(+\frac{4}{9}\div\frac{\left(-5\right)}{7}\)
b ) \((-\frac{3}{5}+\frac{4}{9})\div\frac{7}{11}+(\frac{-2}{5}+\frac{5}{9})\div\frac{7}{11}\)
c ) \(\frac{6}{7}\div(\frac{3}{26}-\frac{3}{13})+\frac{6}{7}\div(\frac{1}{10}-\frac{8}{5})\)
d ) \(A=(2+4+6+........+100)\orbr{\begin{cases}3\\5\end{cases}}\div0,7+3(\frac{-2}{7})]\div(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+......+\frac{1}{100})\)
Giải cụ thể hộ mk vs
\(a,4\frac{5}{9}:\frac{\left(-5\right)}{7}+\frac{4}{9}:\frac{-5}{7}\)
\(=\frac{41}{9}.\frac{-7}{5}+\frac{4}{9}.\frac{-7}{5}\)
\(=\frac{-7}{5}.\left(\frac{41}{9}+\frac{4}{9}\right)\)
\(=-\frac{7}{9}.5\)
\(=-7\)
Đúng 0
Bình luận (0)
a)Bn Kaito Kid làm rùi!
B)Không viết lại đề
\(=\frac{11}{7}\cdot\left(-\frac{3}{5}+\frac{4}{9}-\frac{2}{5}+\frac{5}{9}\right)=\frac{11}{7}\cdot0=0\)
c)Không viết lại đề
\(A=\left(2+4+...+100\right)\left(\frac{3}{5}\cdot\frac{10}{7}-\frac{6}{7}\right):\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{100}\right)\)
\(=\left(2+4+6+...+100\right)\cdot0\cdot\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{100}\right)=0\)
\(=\frac{7}{6}\cdot\left(\frac{3}{26}-\frac{3}{13}+\frac{1}{10}-\frac{8}{5}\right)=\frac{7}{6}\left(\frac{-3}{26}+\frac{-17}{10}\right)=\frac{7}{6}\cdot\frac{236}{130}=\frac{413}{195}\)
D)
Đúng 0
Bình luận (0)
Dòng trên chữ D) là phần c)
Dưới phần c) là phần d) nha!(Lỗi đánh máy)
Đúng 0
Bình luận (0)
a)\(||||x|+\frac{1}{3}|+\frac{1}{3}|+\frac{1}{3}|=1\)
b)\(|\frac{1}{2}x-\frac{2}{3}|-1=\frac{1}{6}\)
c)\(\frac{2}{6}+\frac{2}{12}+\frac{2}{20}+......+\frac{2}{x\left(x+1\right)}=\frac{4}{5}\)
Tìm x
làm giúp mih nha!!!!
a, Đề có vẻ sai sai nhé :v
b, \(\left|\frac{1}{2}x-\frac{2}{3}\right|-1=\frac{1}{6}\)
\(\Leftrightarrow\left|\frac{1}{2}x-\frac{2}{3}\right|=\frac{7}{6}\)
\(\Leftrightarrow\orbr{\begin{cases}\frac{1}{2}x-\frac{2}{3}=\frac{7}{6}\\\frac{1}{2}x-\frac{2}{3}=-\frac{7}{6}\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{11}{3}\\x=-1\end{cases}}\)
Vậy : ....
c, \(\frac{2}{6}+\frac{2}{12}+\frac{2}{20}+...+\frac{2}{x(x+1)}=\frac{4}{5}\)
\(\Leftrightarrow\frac{2}{2\cdot3}+\frac{2}{3\cdot4}+\frac{2}{4\cdot5}+...+\frac{2}{x\cdot(x+1)}=\frac{4}{5}\)
\(\Leftrightarrow2\left[\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{x}-\frac{1}{x+1}\right]=\frac{4}{5}\)
\(\Leftrightarrow2\left[\frac{1}{2}-\frac{1}{x+1}\right]=\frac{4}{5}\)
\(\Leftrightarrow\frac{1}{2}-\frac{1}{x+1}=\frac{2}{5}\)
\(\Leftrightarrow\frac{1}{x+1}=\frac{1}{10}\)
\(\Leftrightarrow x+1=10\Leftrightarrow x=9\)
Vậy x = 9
Đúng 0
Bình luận (0)
tính nhanh nhaDfrac{3}{2x4}+frac{3}{4x6}+...+frac{3}{98x100}Afrac{1}{2}+frac{1}{3}+frac{1}{6}+frac{1}{12}B6frac{2}{3}+7frac{5}{8}+3frac{1}{3}+4frac{5}{8}C[4frac{2}{5}+2frac{3}{7}] - [2frac{2}{5}-1frac{4}{7}]Efrac{131313}{151515}+frac{131313}{353535}+frac{131313}{636363}+frac{131313}{999999}làm ơn giúp mik nhamik đang cần gấpmik sẽ tick(chắc chắn lun) cho người nhanh nhất
Đọc tiếp
tính nhanh nha
D=\(\frac{3}{2x4}+\frac{3}{4x6}+...+\frac{3}{98x100}\)
A=\(\frac{1}{2}+\frac{1}{3}+\frac{1}{6}+\frac{1}{12}\)
B=\(6\frac{2}{3}+7\frac{5}{8}+3\frac{1}{3}+4\frac{5}{8}\)
C=[\(4\frac{2}{5}+2\frac{3}{7}\)] - [\(2\frac{2}{5}-1\frac{4}{7}\)]
E=\(\frac{131313}{151515}+\frac{131313}{353535}+\frac{131313}{636363}+\frac{131313}{999999}\)
làm ơn giúp mik nha
mik đang cần gấp
mik sẽ tick(chắc chắn lun) cho người nhanh nhất
1/3xD=1/(2x4)+1/(4x6)+...+1/(98x100)
2/3xD=2/(2x4)+2/(4x6)+...+1/(98x100)
2/3xD= 1/2-1/4+1/4-1/6+...+1/98-1/100
2/3xD=1/2-1/100
2/3xD=49/100
D=147/200
Đúng 0
Bình luận (0)
A=1/2+1/3+1/6+1/12
A=(1/2+1/3+1/6)+1/12
A=1+1/12
A=13/12
Đúng 0
Bình luận (0)
B=20/3+61/8+10/3+37/8
B=30/3+98/8
B=10+49/4
B=89/4
Đúng 0
Bình luận (0)
Xem thêm câu trả lời