Question

Lex was thinking of a number. Alex divides by 2, then adds 5 to get an answer of 4. What was the original number?

Answer 1

9514 1404 393

Answer:

-2

Explanation:

Let x represent the original number. Then the transformation Alex does is ...

x/2 +5 = 4

x/2 = -1 . . . . subtract 5

x = -2 . . . . . multiply by 2

The original number was -2.