When twice a certain number is subtracted from 11, the result is 5. What is the number?

Question

I need a full explanation please.

Answer 1

Let x = the number in question, i.e. the unknown.

twice that number = 2x

when 2x is subtracted from 11 the result is 5.  This can be written as 11 - 2x = 5

Now solve for x:

-2x = 5 - 11

-2x = -6

2x = 6

x =3 

 

To check this answer:  if you subtract 2 x 3 from 11 do you get 5?

2x3 = 6

11 - 6 = 5 ....check !!