Answer:
Step-by-step explanation:
[tex]-2x-147=123+7x\qquad\text{add 147 to both sides}\\\\-2x-147+147=123+147+7x\\\\-2x=270+7x\qquad\text{subtract }\ 7x\ \text{from both sides}\\\\-2x-7x=270+7x-7x\\\\-9x=270\qquad\text{divide both sides by (-9)}\\\\\dfrac{-9x}{-9}=\dfrac{270}{-9}\\\\x=-30[/tex]