so sánh :

C=\(\frac{5^4.20^4}{25^5.4^5}\) và D=\(\left(\frac{-10}{3}\right)^5.\left(\frac{-6}{5}\right)^4\)

E=\(\left(1+\frac{2}{3}-\frac{1}{4}\right).\left(\frac{4}{5}-\frac{3}{4}\right)^2\)và F=\(2:\left(\frac{1}{2}-\frac{2}{3}\right)^3\)

I=\(\frac{2}{3}+\frac{1}{3}:\left(\frac{-8}{25}\right)\)và H=\(\frac{5}{11}.\frac{4}{11}+\frac{7}{11}.\frac{5}{11}-\frac{2}{3}\)

Bài 1: Thực hiện các phép tính dau bằng cách hợp lí

a. \(\frac{11}{225}-\frac{17}{18}-\frac{5}{7}+\frac{4}{9}+\frac{17}{14}\)

b. \(1-\frac{1}{2}+2-\frac{2}{3}+3-\frac{3}{4}+4-\frac{1}{4}-3-\frac{1}{3}-2-\frac{1}{2}-1\)

Bài 2: Tìm x biết

a. \(\frac{11}{13}-\left(\frac{5}{42}-x\right)=-\left(\frac{15}{28}-\frac{11}{13}\right)\)

b. \(\left|x+\frac{4}{15}\right|-\left|-3,75\right|=-\left|-2,15\right|\)

Bài 3: Thực hiện các phép tính sau bằng cách hợp lí nhất

a. \(\left(-\frac{40}{51}\cdot0,32\cdot\frac{17}{20}\right):\frac{64}{75}\)

b. \(-\frac{10}{11}\cdot\frac{8}{9}+\frac{7}{18}\cdot\frac{10}{11}\)

c. \(\frac{3}{14}:\frac{1}{28}-\frac{13}{21}:\frac{1}{28}+\frac{29}{42}-8\)

d. \(-1\frac{5}{7}\cdot15+\frac{2}{7}.\left(-15\right)+\left(-105\right).\left(\frac{2}{3}-\frac{4}{5}+\frac{1}{7}\right)\)

Bìa 4: Tính giá trị của các biểu thức sau

a. \(A=7x-2x-\frac{2}{3}y+\frac{7}{9}y\) với \(x=-\frac{1}{10};y=4,8\)

b. \(B=x+\frac{0,2-0,375+\frac{5}{11}}{-0,3+\frac{9}{16}-\frac{15}{22}}\) với\(x=-\frac{1}{3}\)

Bỏ ngoặc rồi tính :

a, \(\frac{6}{7}\) + \(\left(\frac{2}{11}-\frac{6}{7}\right)\)- \(\left(\frac{13}{11}+1\right)\)

b, \(\frac{-5}{11}\)- \(\left(\frac{17}{19}-\frac{5}{11}\right)\)- \(\left(\frac{17}{19}-2\right)\)

c, \(-\left(\frac{11}{14}-\frac{8}{9}\right)\)+ \(\left(\frac{-3}{14}-\frac{8}{19}\right)\)

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

1. \(\frac{1}{3}-\frac{3}{5}+\frac{5}{7}-\frac{7}{9}+\frac{9}{11}-\frac{11}{13}+\frac{11}{15}+\frac{11}{13}-\frac{9}{11}+\frac{7}{9}-\frac{5}{7}+\frac{3}{5}-\frac{1}{3}\)
2. \(\frac{-3}{4}.31\frac{11}{23}-0,75.8\frac{12}{28}\)
3. \(\left(2\frac{1}{3}+3\frac{1}{2}\right):\left(-4\frac{1}{6}+3\frac{1}{7}\right)+7\frac{1}{2}\)
4. \(4\frac{5}{9}:\left(-\frac{5}{7}\right)+5\frac{4}{9}:\left(-\frac{5}{7}\right)\)
5. \(\frac{2}{3}-4\left(\frac{1}{2}+\frac{3}{4}\right)\)
6. \(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)....\left(1-\frac{1}{n+1}\right)n\in Z\)

a) A=\(\left(\frac{-5}{11}\right).\frac{7}{15}.\left(\frac{11}{-5}\right).\left(-30\right)\)

b) B=\(\left(-\frac{1}{6}\right).\left(\frac{-15}{19}\right).\left(\frac{38}{45}\right)\)

c) C= \(\left(\frac{-5}{9}\right).\frac{3}{11}+\left(\frac{-13}{18}\right).\frac{3}{11}\)

d) D= \(\left(2\frac{2}{15}.\frac{9}{17}.\frac{3}{32}\right):\left(\frac{-3}{27}\right)\)

Câu 1: Thực hiện phép tính bằng cách hợp lí

\(\frac{15}{35}+\frac{7}{21}+\frac{19}{34}-1\frac{15}{17}+\frac{2}{3}\)

\(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)

\(16\frac{2}{7}:\left(-\frac{3}{5}\right)+28\frac{2}{7}:\left(-\frac{3}{5}\right)\)

Câu 2: Tìm x biết

\(2.x-\frac{5}{4}=\frac{20}{15}\)

\(1,5:0,3=x:-15\)

\(|2x-1|=2\)

Câu 3: Thực hiện phép tính hợp lí

\(\frac{11}{12}.\frac{15}{33}+\frac{11}{12}.\frac{2}{22}\)

\(3/3\frac{1}{8}.11\frac{17}{19}-3\frac{1}{8}.13\frac{17}{19}\)

\(28\frac{2}{7}:\left(-\frac{3}{5}\right)+16\frac{2}{7}:\left(-\frac{3}{5}\right)\)