Tìm x:

a) \(\frac{3}{\left(x+2\right)\cdot\left(x+5\right)}\)+\(\frac{5}{\left(x+5\right)\cdot\left(x+10\right)}\)+\(\frac{7}{\left(x+10\right)\cdot\left(x+17\right)}\)= \(\frac{x}{\left(x+2\right)\cdot\left(x+17\right)}\)

Với x không thuộc (-2;-5;-10;-17)

b) \(\frac{2}{\left(x-1\right)\cdot\left(x-3\right)}\)+\(\frac{5}{\left(x-3\right)\cdot\left(x-8\right)}\)+\(\frac{12}{\left(x-8\right)\cdot\left(x-20\right)}\)-\(\frac{1}{20}\)= \(\frac{-3}{4}\)

Với x không thuộc (1;3;8;20)

c)\(\frac{x+1}{2019}\)+\(\frac{x+2}{2018}\)= \(\frac{x-3}{2017}\)\(\frac{x-4}{2016}\)

bài 1 tính

a)\(-\frac{1}{4}\)  b)\(\left(-2\frac{1}{3}\right)^2\)   c)(0,5)³     d)\(\left(-1\frac{1}{3}\right)^4\)

bai 2 tìm x , biết

a)x:\(\left(-\frac{1}{3}\right)^3\)=\(-\frac{1}{3}\)   b)\(\left(x+\frac{1}{2}\right)^2=\frac{1}{16}\) c)\(\left(\frac{4}{5}\right):x=\left(\frac{4}{5}\right)^7\) d)\(3x+1=27\)

bài 3 so sánh

a)\(10^{20}va9^{10}\) b)\(\left(-5\right)^3^0va\left(-3\right)^{50}\) c)\(64^8va16^{12}\) d)\(\left(\frac{1}{16}\right)^{10}va\left(\frac{1}{2}\right)^{50}\)

\(\left(\frac{-5}{12}+\frac{7}{4}-\frac{3}{8}\right)-\left[4\frac{1}{2}-7\frac{1}{3}\right]-\left(\frac{1}{4}-\frac{5}{2}\right)\)

\(\left[2\frac{1}{4}-5\frac{3}{2}\right]-\left(\frac{3}{10}-1\right)-5\frac{1}{2}+\left(\frac{1}{3}-\frac{5}{6}\right)\)

\(\frac{4}{7}-\left(3\frac{2}{5}-1\frac{1}{2}\right)-\frac{5}{21}+\left[3\frac{1}{2}-4\frac{2}{3}\right]\)

\(\frac{1}{8}-1\frac{3}{4}+\left(\frac{7}{8}-3\frac{7}{2}+\frac{3}{4}\right)-\left[\frac{7}{4}-\frac{5}{8}\right]\)

\(\left(\frac{3}{5}-2\frac{1}{10}+\frac{11}{20}\right)-\left[\frac{-3}{4}+1\frac{7}{2}\right]\)

\(\left[-2\frac{1}{5}-2\frac{2}{3}\right]-\left(\frac{1}{15}-5\frac{1}{2}\right)+\left[\frac{-1}{6}+\frac{1}{3}\right]\)

\(1\frac{1}{8}-\left(\frac{1}{15}-\frac{1}{2}+\frac{-1}{6}\right)+\left[\frac{5}{4}+\frac{3}{2}\right]\)

\(\frac{5}{6}-\left(1\frac{1}{3}-1\frac{1}{2}\right)+\left[\frac{5}{12}-\frac{3}{4}-\frac{1}{6}\right]\)

\(1\frac{1}{4}-\left(\frac{7}{12}-\frac{2}{3}-1\frac{3}{8}\right)+\left[\frac{5}{24}-2\frac{1}{2}\right]-\frac{1}{6}-\left[\frac{-3}{4}\right]\)

\(-2\frac{1}{5}+2\frac{3}{10}-\left(\frac{6}{20}-\left[\frac{2}{8}-1\frac{1}{2}\right]\right)+\left[\frac{7}{20}-1\frac{1}{4}\right]\)

\(-\left[1\frac{2}{3}-3\frac{1}{2}+\frac{1}{4}\right]+\left(\frac{2}{6}-\frac{5}{12}\right)-\left(\frac{1}{3}-\left[\frac{1}{4}-\frac{1}{3}\right]\right)\)

\(-\frac{4}{5}-\left(1\frac{1}{10}-\frac{7}{10}\right)+\left[\frac{3}{4}-1\frac{1}{5}\right]+1\frac{1}{2}\)

\(\frac{3}{21}-\frac{5}{14}+\left[1\frac{1}{3}-5\frac{1}{2}+\frac{5}{14}\right]-\left(\frac{1}{6}-\frac{3}{7}+\frac{1}{3}\right)\)

\(-1\frac{2}{5}+\left[1\frac{3}{10}-\frac{7}{20}-1\frac{1}{4}\right]-\left(\frac{1}{5}-\left[\frac{3}{4}-1\frac{1}{2}\right]\right)\)

\(2\frac{1}{3}-\left(\frac{1}{2}-2\frac{1}{6}+\frac{3}{4}\right)+\left[\frac{5}{12}-1\frac{1}{3}\right]-\frac{7}{8}+3\frac{1}{2}\)

\(2\frac{1}{4}-1\frac{3}{5}-\left(\frac{9}{20}-\frac{7}{10}\right)+\left[1\frac{3}{5}-2\frac{1}{2}\right]+\frac{3}{4}\)

\(\left[\frac{8}{3}-5\frac{1}{4}+\frac{1}{6}\right]-\frac{7}{4}+\frac{-5}{12}-\left(1-1\frac{1}{2}+\frac{1}{3}\right)\)

\(\left(\frac{1}{4}-\left[1\frac{1}{4}-\frac{7}{10}\right]+\frac{1}{2}\right)-2\frac{1}{5}-1\frac{3}{10}+\left[1-\frac{1}{2}\right]\)

TRÌNH BÀY GIÚP MÌNH NHA 

Trong vở bài tập của bạn Dùng có bài làm sau :

a) \(\left(-5\right)^2.\left(-5\right)^3=\left(-5\right)^6\)

b) \(\left(0,75\right)^3:,75=\left(0,75\right)^2\)

c) \(\left(0,2\right)^{10}:\left(0,2\right)^5=\left(0,2\right)^2\)

d) \(\left[\left(-\frac{1}{7}\right)^2\right]^4=\left(-\frac{1}{7}\right)^6\)

e) \(\frac{50^3}{125}=\frac{50^3}{5^3}=\left(\frac{50}{5}\right)^3=10^3=1000\)

f) \(\frac{8^{10}}{4^8}=\left(\frac{8}{4}\right)^{10-8}=2^2\)

Hãy kiểm ta lại các đáp số và sửa lại chỗ sai (nếu có)

1, a) \(\left(\frac{1}{4}\right)^{20}.\left(\frac{1}{2}\right)^5\)      b) \(\left(\frac{1}{9}\right)^{25}:\left(\frac{1}{3}\right)^{20}\)        c) \(\left(\frac{1}{16}\right)^2:\left(\frac{1}{8}\right)^3\)

2, A=\(\frac{10^2-8^2}{6^2}\)          b) B=\(\frac{25^4+10^4}{25^2+16}\)       c) C=\(\frac{9^2.15^3}{3^7.5^2}\)      d) D=\(\frac{6^{10}-3^{10}}{2^{10}-1}\)

Dear thảo :))

\(-1-\frac{1}{3}-\frac{1}{6}-\frac{1}{10}-\frac{1}{15}-...-\frac{1}{45}\)

\(=-1-\left(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{45}\right)\)

\(=-1-2.\left(\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{90}\right)\)

\(=-1-2.\left(\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{9.10}\right)\)

\(=-1-2.\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{9}-\frac{1}{10}\right)\)

\(=-1-2.\left(\frac{1}{2}-\frac{1}{10}\right)\)

\(=-1-2.\frac{2}{5}\)

\(=\frac{-9}{5}\)