Tìm x , biết:a. x + = 2,5 ×1,5 ,

* Hướng dẫn giải

$\begin{array}{l}a)x+\frac{4}{5}=2,5\times 1,5\\ x+\frac{4}{5}=3,75\\ x=3,75-\frac{4}{5}\\ x=2,95\end{array}$

$\begin{array}{l}b) 4,775-x=4,775+3,6\times \left(0,01-\frac{1}{100}\right)\\ 4,775-x=4,775+3,6\times 0\\ 4,775-x=4,775\\ x=4,775-4,775\\ x=0\end{array}$