Question

Factorise:
$z-7+7xy-xyz$

• A. $(z-xy)(1-xz)$
• B. $(z-7)(1-xy)$
• C. $z(7-xzy)$
• D. $(z+7)(x-y)$

Answer 1

The correct option is B $(z-7)(1-xy)$

$z-7+7xy-xyz$
$=z-7-xyz+7xy$
$=1(z-7)-xy(z-7)$
$=(z-7)(1-xy)$
[Taking $z-7$ common]