a number decreased by 7 gives twice the number

Question

I keep writing the equation but cannot get a whole number answer

 

Answer 1

The correct equation to describe this scenario is

 

n - 7 = 2n

 

Solve for n and get

 

-7 = 2n - n = n

 

n = -7

 

Test the answer.

 

-7 - 7 = -14 = 2(-7)  [good]