b) x-60/4+x-58/3+x-56/2+x=69

* Hướng dẫn giải

b, Ta có

$$\begin{gathered} \frac{x-60}{4}+\frac{x-58}{3}+\frac{x-56}{2}+x=69 \\ \iff \left(\frac{x-60}{4}-1\right)+\left(\frac{x-58}{3}-2\right)+\left(\frac{x-56}{2}-4\right)+\left(x-64\right)=0 \\ \iff \frac{x-64}{4}+\frac{x-64}{3}+\frac{x-64}{2}+x-64=0 \\ \iff \left(x-64\right)\left(1+\frac{1}{4}+\frac{1}{3}+\frac{1}{2}\right)=0 \end{gathered}$$