Question

factorise the following expressions:z^2-4z-77

Answer 1

Here is your answer..

z²-4z-77
z²-11z+7z-77
z(z-11)+7(z-11)
(z-11)(z+7)

Hope it will help :-)

Answer 2

z^2 - 4z - 77
=z^2 +7z - 11z - 77
=z(z + 7) -11(z + 7)
=(z + 7)(z - 11)