Please show solution to simplifying this expression:

Question

( 5z-2 )( 5z+2)

Thank you.

Answer 1

(5z-2)(5z+2) = 25z^2 +10z - 10z - 4 = 25z^2 - 4.

or (5z)^2 - 2^2 = 25z^2 - 4.