ranslate into a variable expression. Then simplify. (Use x to represent the number.)

a number decreased by the total of the number and eighteen

x - x + 18

To translate the given expression into a variable expression, we can start by representing the unknown number as 'x'.

According to the expression, "a number decreased by the total of the number and eighteen," we can break it down into two parts:

1. The total of the number and eighteen: x + 18
2. The number decreased by the total: x - (x + 18)

Now, let's simplify the variable expression:
x - (x + 18) = x - x - 18
= -18

Therefore, the simplified variable expression for "a number decreased by the total of the number and eighteen" is -18.