Question

(z–20)(z+20)

Answer 1

difference of perfect squares, so you do what i told you last time, z times z is \[z ^{2}\] and - 20 times 20 is -400

Answer 2

the answer is \[z ^{2}-400\]

Answer 3

(5a+2)(5a–2)

Answer 4

is it the same thing

Answer 5

yep! so what answer do you get

Answer 6

25a2-1

Answer 7

a squar

Answer 8

close, but what is 2 times -2

Answer 9

-1