Which expressions are differences of squares?

Choose all answers that are correct.

Question 2 options:

8b^2 - 16c^6

16e^8 - 81g^4

49x^25 - 4y^16

121m^18 - 9n^10

Difference of 2 perfec squares is

(a^2) - (b^2)

if the exponents are both even and the coeficient (the number in front) are perfect squares, then it is difference t 2 perfect squares

first one

8 is not perfect square

2nd one

(4e^4) ^2 - (9g^2) ^2

third

25 is odd, so it cannot be split up into 2 nice numbers

4th

(11m^9) ^2 - (3n^5) ^2