Solve for X: Finding the Variable in 72-x=63

To solve the question, we need to isolate X.

Since in this case X is negative, we will move it to the other side.

(Remember that when moving terms between sides, their signs change - from positive to negative and from negative to positive).

$72=63+x$

Now, we will also move the 63 to the other side.

(Remember that 63 becomes negative when moving sides).

$72-63=x$

And now let's solve the subtraction exercise:

$9=x$