will mark brainliest, 60 points

Answer:
21 C
22 B
23 169
Step-by-step explanation:
21 3m mean 3 times a certain number
22 the negative make the 4 go negative and the -5 positive
23 i did 5^2-4^2= 9
then 6^2 divided by 9+9= 13 i took the 9 from the 5^2 problem then divided it by 6^2
then 13 x 13 = 169