Question

The sum of a number and 9 is 12.

Answer 1

Answer:

x=3

Step-by-step explanation:

You take 12-9 to get 3 :)

Answer 2

Answer:

$3$

Step-by-step explanation:

Simple, all you have to do is backwards equation. If the sum is 12. Subtract 12 by one of the numbers given.

$12 - 9$

$==> 3$

$3 + 9 = 12$