Question

The sum of a number and three is six less than twice that number

Answer 1

Algebraic expression = x+3=2x-6

Explanation:

Let the unknown number be x ;

`x+3 =2x-6`

Further explanation

`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\\(-x)/(-1)=(-9)/(-1)\\\\x =9`