a) \(x + \frac{5}{6} = \frac{4}{3}\)

\(x = \frac{4}{3} - \frac{5}{6} = \frac{8}{6} - \frac{5}{6}\)

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

b) \(x : 2^{4} = 8^{3}\)

\(x : 2^{4} = \left(\right. 2^{3} \left.\right)^{3}\)

\(x : 2^{4} = 2^{9}\)

\(x = 2^{9} . 2^{4} = 2^{13}\)

c) \(\frac{13}{4} . \left(\right. \frac{5}{52} - x \left.\right) = \frac{1}{4}\)

\(\frac{5}{52} - x = \frac{1}{4} : \frac{13}{4}\)

\(\frac{5}{52} - x = \frac{1}{13}\)

\(x = \frac{5}{52} - \frac{1}{13}\)

\(x = \frac{1}{52}\)

a) \(\frac{5}{9} - \left(\left(\right. \frac{1}{3} \left.\right)\right)^{2} = \frac{5}{9} - \frac{1}{9} = \frac{4}{9}\)

b) \(\frac{1}{5}.\frac{- 3}{2}+\frac{- 17}{2}.\frac{1}{5}\)

\(= \frac{1}{5} . \left(\right. \frac{- 3}{2} + \frac{- 17}{2} \left.\right)\)

\(= \frac{1}{5} . \left(\right. - 10 \left.\right) = - 2\)

c) \(1 + \left(\right. \frac{- 2}{5} + \frac{11}{13} \left.\right) - \left(\right. \frac{3}{5} - \frac{2}{13} \left.\right)\)

\(= 1 + \frac{- 2}{5} + \frac{11}{13} - \frac{3}{5} + \frac{2}{13}\)

\(= 1 + \left(\right. \frac{- 2}{5} - \frac{3}{5} \left.\right) + \left(\right. \frac{11}{13} + \frac{2}{13} \left.\right)\)

\(= 1 + \left(\right. - 1 \left.\right) + 1 = 1\)

Dọc theo chiều dài, ta trồng được:

\(5.5 : \frac{1}{4} = 22\) (khóm hoa)

Dọc theo chiều rộng, ta trồng được:

\(3 , 75 : \frac{1}{4} = 15\) (khóm hoa)

Như vậy, số khóm hoa trồng được dọc theo hai cạnh của mảnh vườn là:

\(\left[\right. \left(\right. 22 + 15 \left.\right) . 2 \left]\right. - 4 = 70\) (khóm hoa)

a) \(\frac{1}{5}+\frac{4}{5}:x=0,75\)

\(a)\frac{1}{5}+\frac{4}{5}:x=\frac{3}{4}\)

\(\frac{4}{5} : x = \frac{3}{4} - \frac{1}{5}\)

\(\frac{4}{5} : x = \frac{11}{20}\)

\(x = \frac{16}{11}\);

b) \(x + \frac{1}{2} = 1 - x\)

 \(2 x = 1 - \frac{1}{2}\)

 \(2 x = \frac{1}{2}\)

 \(x = \frac{1}{4}\).

a) \(\frac{2}{3} \cdot \frac{5}{4} - \frac{3}{4} \cdot \frac{2}{3} = \frac{2}{3} \cdot \left(\right. \frac{5}{4} - \frac{3}{4} \left.\right) = \frac{2}{3} \cdot \frac{1}{2} = \frac{1}{3}\);
b) \(2 \cdot \left(\left(\right. \frac{- 3}{2} \left.\right)\right)^{2} - \frac{7}{2} = 2 \cdot \frac{9}{4} - \frac{7}{2} = \frac{9}{2} - \frac{7}{2} = 1\);
c) \(- \frac{3}{4} \cdot 5 \frac{3}{13} - 0 , 75 \cdot \frac{36}{13} = - \frac{3}{4} \cdot 5 \frac{3}{13} - \frac{3}{4} \cdot \frac{36}{13}\)
\(= - \frac{3}{4} \left(\right. 5 \frac{3}{13} + \frac{36}{13} \left.\right)\)
\(= - \frac{3}{4} \cdot 8 = - 6\).