tính giá trị của biểu thức M=\(1+\frac{1}{2}.\left(1+2\right)+\frac{1}{3}.\left(1+2+3\right)+\frac{1}{4}.\left(1+2+3+4\right)+...+\frac{1}{16}.\left(1+2+3+...+16\right)\)
Tính Giá Trị Của Biểu Thức
\(\left[18\frac{1}{6}-\left(0,06:7\frac{1}{2}+3\frac{2}{5}.0.38\right)\right]:\left[16-2\frac{2}{3}.4\frac{3}{4}\right]\)
\(\left[18\frac{1}{6}-\left(0,06:7\frac{1}{2}+3\frac{2}{5}\cdot0,38\right)\right]:\left[16-2\frac{2}{3}\cdot4\frac{3}{4}\right]\)
\(< =>\left[18\frac{1}{6}-\left(\frac{1}{125}+\frac{323}{250}\right)\right]:\left[16-\frac{38}{3}\right]\)
\(< =>\left[18\frac{1}{6}-\frac{13}{10}\right]:\frac{10}{3}\)
\(< =>\frac{253}{15}:\frac{10}{3}\)
\(< =>\frac{253}{50}\)
Tính giá trị biểu thức \(A=1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+\frac{1}{4}+\left(1+2+3+4\right)+...+\frac{1}{16}+\left(1+2+3+...+16\right)\)
Giúp mk mn ơi
\(A=1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+\frac{1}{4}\left(1+2+3+4\right)+...+\frac{1}{16}\left(1+2+3+...+16\right)\)
\(A=1+\frac{1+2}{2}+\frac{1+2+3}{3}+\frac{1+2+3+4}{4}+...+\frac{1+2+3+...+16}{16}\)
\(A=1+\frac{2\left(2+1\right):2}{2}+\frac{3\cdot\left(3+1\right):2}{3}+\frac{4\left(4+1\right):2}{4}+...+\frac{16\left(16+1\right):2}{16}\)
\(A=1+\frac{2+1}{2}+\frac{3+1}{2}+\frac{4+1}{2}+...+\frac{16+1}{2}\)
\(A=\frac{2}{2}+\frac{3}{2}+\frac{4}{2}+\frac{5}{2}+...+\frac{17}{2}\)
\(A=\frac{2+3+4+5+...+17}{2}\)
\(A=\frac{152}{2}\)
\(A=76\)
Tính giá trị biểu thức
1, \(\frac{1}{16}-\frac{5}{21}+\left(\frac{-1}{16}+\frac{-3}{5}-\frac{-5}{21}\right)+\frac{-2}{3}+\frac{3}{4}\)
2, \(\left(\frac{5}{8}-\frac{4}{13}+\frac{3}{2}\right)-\left(\frac{5}{8}+\frac{9}{13}\right)-\left|\frac{-3}{2}\right|+\frac{-7}{15}\)
Bài 1 Tính giá trị của biểu thức
a) \(A=\left(\frac{\frac{1}{3}-\frac{1}{7}-\frac{1}{13}}{\frac{2}{3}-\frac{2}{7}-\frac{2}{13}}\right)\cdot\left(\frac{\frac{3}{4}-\frac{3}{16}-\frac{3}{64}-\frac{3}{256}}{1-\frac{1}{4}-\frac{1}{64}}\right)\)
b)\(B=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{10}\right)...\left(1-\frac{1}{210}\right)\)
c)10.11+11,12+12,13+...+98,99+99,100
Bạn ơi, có phải bạn viết sai đề câu c không?
\(10,11+11,12+12,13+...+98,99+99,100\)
1/ Tính giá trị biểu thức
A=\(\frac{7}{35}+\left(-1\frac{3}{4}+\frac{12}{7}\right)-\left(\frac{1}{4}-\frac{2}{7}-\frac{13}{35}\right)-\frac{3}{7}\)\(\frac{3}{7}\)
B=\(\sqrt{\frac{25}{16}-\frac{\left(-3\right)^2}{\left|-4\right|}}+\frac{\sqrt{\left(-7\right)^2}}{4}-3.\left(\frac{5}{2}\right)^2\)
Tính giá trị biểu thức:
\(\left[18\frac{1}{6}-\left(0,06:7\frac{1}{2}+3\frac{2}{5}.0,85\right)\right]\) \(:\left(16-2\frac{2}{3}:4\frac{3}{4}\right)\)
Tính giá trị biểu thức :
\(A=\left(3\sqrt{3}\right)^{\frac{4}{3}}+\left(\frac{1}{16}\right)^{\frac{3}{4}}+2\left(\frac{8}{27}\right)^{\frac{2}{3}}\)
\(A=\left(3\sqrt{3}\right)^{\frac{4}{3}}+\left(\frac{1}{16}\right)^{\frac{3}{4}}+2\left(\frac{8}{27}\right)^{\frac{2}{3}}\)
\(A=\left(3\sqrt{3}\right)^{\frac{4}{3}}+55+\frac{32}{3}\)
\(A=\left(3\sqrt{3}\right)^{\frac{4}{3}}+\frac{197}{3}\)
\(A=243+\frac{197}{3}\)
\(A=\frac{926}{3}\)
Ta có \(A=3^{\frac{3}{2}.\frac{4}{3}}+\left(\frac{1}{2}\right)^{4.\frac{3}{4}}+2\left(\frac{2}{3}\right)^{3.\frac{2}{3}}=3^2+\left(\frac{1}{2}\right)^3+2\left(\frac{2}{3}\right)^2=\frac{721}{72}\)
Ta có:
\(A=\left(3\sqrt{3}\right)^{\frac{4}{3}}+\left(\frac{1}{6}\right)^{\frac{3}{4}}+2\left(\frac{8}{27}\right)^{\frac{2}{3}}=9+\frac{3}{32}+\frac{4}{9}=9\frac{155}{288}\)
Cho biểu thức: \(A = \left( {2 + \frac{1}{3} - \frac{2}{5}} \right) - \left( {7 - \frac{3}{5} - \frac{4}{3}} \right) - \left( {\frac{1}{5} + \frac{5}{3} - 4} \right).\)
Hãy tính giá trị của A theo hai cách:
a) Tính giá trị của từng biểu thức trong dấu ngoặc trước.
b) Bỏ dấu ngoặc rồi nhóm các số hạng thích hợp.
a)
\(\begin{array}{l}A = \left( {2 + \frac{1}{3} - \frac{2}{5}} \right) - \left( {7 - \frac{3}{5} - \frac{4}{3}} \right) - \left( {\frac{1}{5} + \frac{5}{3} - 4} \right).\\A = \left( {\frac{{30}}{{15}} + \frac{5}{{15}} - \frac{6}{{15}}} \right) - \left( {\frac{{105}}{{15}} - \frac{9}{{15}} - \frac{{20}}{{15}}} \right) - \left( {\frac{3}{{15}} + \frac{{25}}{{15}} - \frac{{60}}{{15}}} \right)\\A = \frac{{29}}{{15}} - \frac{{76}}{{15}} - \left( {\frac{{ - 32}}{{15}}} \right)\\A = \frac{{29}}{{15}} - \frac{{76}}{{15}} + \frac{{32}}{{15}}\\A = \frac{{ - 15}}{{15}}\\A = - 1\end{array}\)
b)
\(\begin{array}{l}A = \left( {2 + \frac{1}{3} - \frac{2}{5}} \right) - \left( {7 - \frac{3}{5} - \frac{4}{3}} \right) - \left( {\frac{1}{5} + \frac{5}{3} - 4} \right)\\A = 2 + \frac{1}{3} - \frac{2}{5} - 7 + \frac{3}{5} + \frac{4}{3} - \frac{1}{5} - \frac{5}{3} + 4\\A = \left( {2 - 7 + 4} \right) + \left( {\frac{1}{3} + \frac{4}{3} - \frac{5}{3}} \right) + \left( { - \frac{2}{5} + \frac{3}{5} - \frac{1}{5}} \right)\\A = - 1 + 0 + 0 = - 1\end{array}\)
tính: \(1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+\frac{1}{4}\left(1+2+3+4\right)+...+\frac{1}{16}\left(1+2+3+...+16\right)\)
Đặt \(A=1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+\frac{1}{4}\left(1+2+3+4\right)+...+\frac{1}{16}\left(1+2+3+...+16\right)\)
\(A=1+\frac{1+2}{2}+\frac{1+2+3}{3}+\frac{1+2+3+4}{4}+...+\frac{1+2+3+...+16}{16}\)
\(A=1+\frac{2\left(2+1\right):2}{2}+\frac{3\left(3+1\right):2}{3}+\frac{4\left(4+1\right):2}{4}+...+\frac{16\left(16+1\right):2}{16}\)
\(A=1+\frac{2+1}{2}+\frac{3+1}{2}+\frac{4+1}{2}+...+\frac{16+1}{2}\)
\(A=\frac{2}{2}+\frac{3}{2}+\frac{4}{2}+\frac{5}{2}+...+\frac{17}{2}\)
\(A=\frac{2+3+4+5+...+17}{2}\)
\(A=\frac{152}{2}\)
\(A=76\)