Answer:
1 is 9 sq units
2 is 12
3 is 24cm^2
Step-by-step explanation:
You could rewrite

as

and be tempted to cancel out the factors of

. But this cancellation is only valid when

.
When

, you end up with the indeterminate form

, which is why

is not a zero.
7+ (-5) = 2.
Therefor, 4^2 would be the right answer.