Tìm x, biết: a) 3 1/5 x - 4 2/3 = 3 1/3 b) 2 2/3 x + 3 3/4 x = 385/24

* Hướng dẫn giải

a) $3\frac{1}{5}x-4\frac{2}{3}=3\frac{1}{3}\Rightarrow 3\frac{1}{5}x=3\frac{1}{3}+4\frac{2}{3}=8$$\Rightarrow x=8:\frac{16}{5}=8.\frac{5}{16}=\frac{5}{2}$

b) $2\frac{2}{3}x+3\frac{3}{4}x=\frac{385}{24}\Rightarrow x\left(2\frac{2}{3}+3\frac{3}{4}\right)=\frac{385}{4}$$\Rightarrow x.\frac{77}{12}=\frac{385}{4}\Rightarrow x=\frac{385}{4}:\frac{77}{12}=15$