What is two even numbers that have a gcf of 2

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

Simplify (2^5/3^2)^4 a. 2^20/3^8 b. 2^9/3^8 c. 8^5/12^2 d. 2/3^2

Idon't want to fail summer school.the probabilities of contamination in medicine capsules due to the presence of heavy metals and different types of microbes are given in the table.the probability of capsule b having microbial contamination is (the same as, greater than, less than) the probability of capsule d having it.