Answer:
Algebraic expression = x+3=2x-6
Step-by-step explanation:
Let the unknown number be x ;
[tex]x+3 =2x-6[/tex]
Further explanation
[tex]x+3=2x-6\\\\\mathrm{Subtract\:}3\mathrm{\:from\:both\:sides}x+3-3=2x-6-3\\\\Simplify\\x=2x-9\\\\Collect\:like\:terms\\x-2x =-9\\\\Simplify\\-x =-9\\\\\mathrm{Divide\:both\:sides\:by\:}-1\\\frac{-x}{-1}=\frac{-9}{-1}\\\\x =9[/tex]
