need algebra help quick 5

1. Which binomial is a difference of squares?

 
 

Question 2.2. Factor:25m^6-16

 
(5
m
3 + 4)(5
m
3 â€“ 4)

 
 

Question 3.3. Factor: 64a^2b^36-1

 
(8
ab
18 + 1)(8
ab
18 â€“ 1)

 
 

Question 4.4. What is the completed factored form of 2x2 â€“ 50?

 
 

Question 5.5. Nicole is factoring 0.49t18 â€“ 25 by using the rule a2 â€“ b2 = (a + b)(a â€“ b). What will she use for the value of a?