\(=\frac{5}{3}\cdot\frac{7}{5}\cdot\frac{6}{5}==\frac{5\cdot7\cdot6}{3\cdot5\cdot5}=\frac{14}{5}\)

\(\sqrt{2\frac{7}{9}\cdot}\sqrt{1\frac{24}{25}}\cdot\sqrt{\frac{36}{25}}\)

\(\Leftrightarrow\sqrt{\frac{25}{9}}\cdot\sqrt{\frac{49}{25}}\cdot\sqrt{\frac{36}{25}}\)

\(\Leftrightarrow\frac{5}{3}\cdot\frac{7}{5}\cdot\frac{6}{5}\)\(=\frac{5\cdot7\cdot6}{3\cdot5\cdot5}=\frac{210}{75}=\frac{14}{5}\)

\(F\left(x\right)=x^2-3x^3-\sqrt{25}+\frac{1}{2}x-\left(-3x^3+\frac{5x}{2}-\sqrt{36}\right)\)

=> \(F\left(x\right)=x^2-3x^3-5+\frac{1}{2}x+3x^3-\frac{5x}{2}+6\)

=> \(F\left(x\right)=x^2+\left(3x^3-3x^3\right)+\left(6-5\right)+\left(\frac{x}{2}-\frac{5x}{2}\right)\)

=> \(F\left(x\right)=x^2+1-2x\)

\(\frac{x^2-36}{2x+10}\cdot\frac{3}{6-x}=\frac{\left(x-6\right)\left(x+6\right)}{2x+10}\cdot\frac{3}{6-x}=-\frac{3\left(x+6\right)}{2x+10}=-\frac{3x+18}{2x+10}\)

\(\frac{x^2-4}{x^2-9}\cdot\frac{3x+9}{x+2}=\frac{\left(x-2\right)\left(x+2\right)}{\left(x+3\right)\left(x-3\right)}\cdot\frac{3\left(x+3\right)}{x+2}=\frac{3\left(x-2\right)}{x-3}\)

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

\(\frac{4x+12}{\left(x+4\right)^2}:\frac{3x+9}{x+4}=\frac{4\left(x+3\right)}{\left(x+4\right)^2}\cdot\frac{x+4}{3\left(x+3\right)}=\frac{4}{3\left(x+4\right)}\)

8/5:(8/5.5/4) / 16/25-1/25 + 1:4/7 / (50/9-9/4).36/17) + 0,6.0,5:2/5

= 8/5:8/5:5/4 / 3/5 + 7/4 / 50/9.36/17-9/4.36/17 + 0,3.5/2

= 4/5:3/5 + 7/4 / 200/17-81/17 + 3/10.5/2

= 4/5.5/3 + 7/4 / 119/17 + 3/4

= 4/3 + 7/4 : 7 + 3/4

= 4/3 + 4 + 3/4

= 16/12 + 48/12 + 9/12

= 73/12

☆★☆★☆

73/12

a, 15 + 3x = 3

3x = 3 - 15

3x = -12

x = -4

b, 1\(\frac{3}{2}\)x - \(\frac{6}{7}\) = \(\frac{1}{8}\)

\(1\frac{3}{2}\)x = \(\frac{1}{8}+\frac{6}{7}\)

\(1\frac{3}{2}\)x = \(\frac{55}{56}\)

x = \(\frac{55}{56}:1\frac{3}{2}\)

x = \(\frac{11}{28}\)

c, Ta có: \(\frac{-36}{48}=\frac{-3}{4}\); \(\frac{-25}{35}=\frac{-5}{7}\)

Quy đồng mẫu số 2 phân số ta được:

\(\frac{-21}{28}\) và \(\frac{-20}{28}\)

Vì -21 < -20 \(\Rightarrow\) \(\frac{-21}{28}< \frac{-20}{28}\) hay \(\frac{-36}{48}< \frac{-25}{35}\)

Chúc bn học tốt

\(3x=\frac{7}{25}+\frac{-1}{5}\)

\(3x=\frac{2}{25}\)

  \(x=\frac{2}{25}:3\)

  \(x=\frac{2}{75}\)

\(3x=\frac{7}{25}+\frac{-1}{5}\)

\(3x=\frac{2}{25}\)

\(x=\frac{2}{25}:3\)

\(x=\frac{2}{25}.\frac{1}{3}\)

\(x=\frac{2}{75}\)

chúc bạn học giỏi