what is the answer. x+23=12?

x=-11

The question means that 23 must be added to a number to make 12.

It's obvious that it cannot be a positive number as the answer of the equation is less than 23, so it is a negative value.

x = 12 - 23
therefore, x = -11.

You can always check on a calculator if you feel you have made a basic arithmetic error on these questions because many people do on this sort of question. :)

x + 23 = 12
x + 23 - 23 = 12 - 23
x = -11

x = -11
Subtract both sides of the equation by 23 like this:
x+23-23=12-23
x +0 = -11, therefore
x = -11

x=-11

you take the 23 and you place it on the other side of the = sign
x=-23+12
* note: whenever you do so that number becomes the opposite sign (the 23 turns from positive to negative)

and then you add it together
-23+12=-11

x+23=12

get X by itself

x+23=12
-23 -23
x + 0 -11
x = -11

subtract 23 from 12.
-11.

x + 23 = 12
x = 12-23
x= -11

x + 23 = 12
x + 23 - 23 = 12 - 23
x = -11

Subtract 23 from both sides:
x = -11 <==Answer