Làm hộ mình bài 4 và bài 5

Giải thích các bước giải:

Bài 4:

$\begin{aligned}
1) & \quad x + \dfrac{1}{3} = \dfrac{-7}{3} \\
& \Leftrightarrow x = \dfrac{-7}{3} - \dfrac{1}{3} \\
& \Leftrightarrow x = \dfrac{-8}{3} \\
\\
2) & \quad \dfrac{1}{8} - x = \dfrac{3}{8} \\
& \Leftrightarrow x = \dfrac{1}{8} - \dfrac{3}{8} \\
& \Leftrightarrow x = \dfrac{-2}{8} = \dfrac{-1}{4} \\
\\
3) & \quad x - \dfrac{4}{5} = \dfrac{6}{5} \\
& \Leftrightarrow x = \dfrac{6}{5} + \dfrac{4}{5} \\
& \Leftrightarrow x = \dfrac{10}{5} = 2 \\
\\
4) & \quad \dfrac{2}{3} + x = \dfrac{7}{3} \\
& \Leftrightarrow x = \dfrac{7}{3} - \dfrac{2}{3} \\
& \Leftrightarrow x = \dfrac{5}{3} \\
\\
6) & \quad x - \dfrac{1}{2} = \dfrac{9}{2} \\
& \Leftrightarrow x = \dfrac{9}{2} + \dfrac{1}{2} \\
& \Leftrightarrow x = \dfrac{10}{2} = 5 \\
\\
7) & \quad x + \dfrac{5}{4} = \dfrac{-3}{4} \\
& \Leftrightarrow x = \dfrac{-3}{4} - \dfrac{5}{4} \\
& \Leftrightarrow x = \dfrac{-8}{4} = -2 \\
\\
8) & \quad x + \dfrac{2}{7} = \dfrac{5}{7} \\
& \Leftrightarrow x = \dfrac{5}{7} - \dfrac{2}{7} \\
& \Leftrightarrow x = \dfrac{3}{7} \\
\\
9) & \quad x - \dfrac{4}{3} = \dfrac{1}{3} \\
& \Leftrightarrow x = \dfrac{1}{3} + \dfrac{4}{3} \\
& \Leftrightarrow x = \dfrac{5}{3}
\end{aligned}$

Bài 5:

 $\begin{aligned}
1) & \quad x + \dfrac{1}{2} = \dfrac{-5}{3} \\
& \Leftrightarrow x = \dfrac{-5}{3} - \dfrac{1}{2} \\
& \Leftrightarrow x = \dfrac{-10 - 3}{6} \\
& \Leftrightarrow x = \dfrac{-13}{6} \\
\\
2) & \quad \dfrac{1}{3} - x = \dfrac{3}{5} \\
& \Leftrightarrow x = \dfrac{1}{3} - \dfrac{3}{5} \\
& \Leftrightarrow x = \dfrac{5 - 9}{15} \\
& \Leftrightarrow x = \dfrac{-4}{15} \\
\\
3) & \quad \dfrac{3}{4} + x = \dfrac{7}{2} \\
& \Leftrightarrow x = \dfrac{7}{2} - \dfrac{3}{4} \\
& \Leftrightarrow x = \dfrac{14 - 3}{4} \\
& \Leftrightarrow x = \dfrac{11}{4} \\
\\
4) & \quad x - \dfrac{4}{3} = \dfrac{-7}{9} \\
& \Leftrightarrow x = \dfrac{-7}{9} + \dfrac{4}{3} \\
& \Leftrightarrow x = \dfrac{-7 + 12}{9} \\
& \Leftrightarrow x = \dfrac{5}{9} \\
\\
6) & \quad x - \dfrac{1}{5} = \dfrac{9}{10} \\
& \Leftrightarrow x = \dfrac{9}{10} + \dfrac{1}{5} \\
& \Leftrightarrow x = \dfrac{9 + 2}{10} \\
& \Leftrightarrow x = \dfrac{11}{10} \\
\\
7) & \quad x + \dfrac{5}{12} = \dfrac{3}{8} \\
& \Leftrightarrow x = \dfrac{3}{8} - \dfrac{5}{12} \\
& \Leftrightarrow x = \dfrac{9 - 10}{24} \\
& \Leftrightarrow x = \dfrac{-1}{24} \\
\\
8) & \quad x + \dfrac{5}{4} = \dfrac{7}{6} \\
& \Leftrightarrow x = \dfrac{7}{6} - \dfrac{5}{4} \\
& \Leftrightarrow x = \dfrac{14 - 15}{12} \\
& \Leftrightarrow x = \dfrac{-1}{12} \\
\\
9) & \quad x - \dfrac{2}{7} = \dfrac{1}{35} \\
& \Leftrightarrow x = \dfrac{1}{35} + \dfrac{2}{7} \\
& \Leftrightarrow x = \dfrac{1 + 10}{35} \\
& \Leftrightarrow x = \dfrac{11}{35}
\end{aligned}$