Question 10
Ms. Dao has to place each of the digits $1,3,4,6,7,8$ and $9$ into one of the boxes below, using each digit exactly once, to make a correct equality.
$$\square+\square-\square-\square+\square+\square-\square=2$$
In how many different ways can she do it?
(Note: Two solutions are considered different if the numbers they filled in differ in at least one box.)
$$\square+\square-\square-\square+\square+\square-\square=2$$
In how many different ways can she do it?
(Note: Two solutions are considered different if the numbers they filled in differ in at least one box.)