Tìm số nguyên x biết: a) x:(-9) = -54 b) x:(-12) = 18 c) x:(-5) = -19

* Hướng dẫn giải

$\begin{array}{l}a)\text{x}:\left(-\text{9}\right)=-\text{54}\\ \text{ x }=-\text{54}.\left(-\text{9}\right)\\ \text{ x }=\text{486}\end{array}$

$\begin{array}{l}b)\text{x }:\left(-\text{12}\right)=\text{ 18}\\ \text{ x }=\text{ 18}.\left(-\text{12}\right)\\ \text{ x }=-\text{216}\end{array}$

$\begin{array}{l}c)\text{x}:\left(-\text{5}\right)=-\text{19}\\ \text{ x }=-\text{19}.\left(-\text{5}\right)\\ \text{ x }=\text{ 95}\end{array}$