#### Answer

$x=25$

#### Work Step by Step

We are told when a number is subtracted from five times the number, the result is 100. We will use x as the variable. Therefore, the difference between 5x and x equals 100.
$5x-x=100$
Combine like terms on the left side.
$5x-x=(5-1)x=4x=100$
Divide both sides by 4.
$x=25$