Answer:
a b
m n
the 2nd one
Step-by-step explanation:
Try 9cm but I’m not quite sure please reply if it’s wrong or right
The answer is -4 because -4 times -3 equals -12
Answer:
Proof for 
Step-by-step explanation:
We are given that a, n, b, r and k are integers.
Also,

Since k divides a and b, we can write,
a = rk and b = sk, where r and s are integers.
Now, we have to prove that k divides r as well that is 
Putting value of a and b in the equation, we get:

Since, (r-sn) is an integer, k divides r.
I also need this too pleaseee huryy