Question

Factorize the following expressions.
(i) $z^2+6z+8$
(ii) $z^2-10z+21$
(iii) $z^2+6z-16$

Answer 1

(i) $z^2+6z+8$

$z^2+2z+4z+8$

$2(z+2)+4(z+2)$

$(z+4)(z+2)$

(ii) $z^2-10z+21$

$z^2-7z-3z+21$

$z(z-7)-3(z-7)$

$(z-3)(z-7)$

(iii) $z^2+6z-16$

$z^2+8z-2z-16$

$z(z+8)-2(z+8)$

$(z-2)(z+8)$