Tìm x a. x - 3 / 4 = 3 / 5; b. x : 1 / 4 = 16

* Hướng dẫn giải

$$\begin{gathered} \mathrm{a}. \mathrm{x} - \frac{3}{4} = \frac{3}{5} \\ \mathrm{x} = \frac{3}{5} + \frac{3}{4} \\ \mathrm{x}=\frac{27}{20} \end{gathered}$$

$$\begin{gathered} \mathrm{b}. \mathrm{x}\hspace{0.17em}: \frac{1}{4}=16 \\ \mathrm{x}=16\mathrm{x}\frac{1}{4} \\ \mathrm{x} = 4 \end{gathered}$$