16 less than a number equals - 19. what is the number?

We'll use x to represent the mystery number.

"Sixteen less than" means subtraction, so we have 16 -

"Less than a number" simply means 16 - x

"Equals - 19" sets 16 - x equal to - 19. In other words, 16 - x = - 19

To solve, we subtract 16 to get x alone:

-x = - 35

Divide the entire equation by - 1 to make x positive:

-1 (-x = - 35) leaves us with x = 35

The number is - 3 because - 3 minus 16 equals - 19.