Answer:
12
Step-by-step explanation
so what I did is I divided 15 by 5 to get 3 also 9 divided by 3 equals 3 to so you could of also done that.
then i multiplied to 4 x 3 to get the missing side length which equals 12
Answer with Step-by-step explanation:
Let F be a field .Suppose
and 
We have to prove that a has unique multiplicative inverse.
Suppose a has two inverses b and c
Then,
where 1 =Multiplicative identity

(cancel a on both sides)
Hence, a has unique multiplicative inverse.
Answer: 3/4
Step-by-step explanation: 12/16 which simplifies to 3/4.
DONT OPEN THE ANSWER ABOVE ITS A VIRUS. i will give an answer in the comments though