Answer
7 (a). $ x (x - y)$
7 (b). $ \sin\theta (\sin\theta- \cos\theta)$
Work Step by Step
7 (a). Given expression is-
$x^{2} - xy$
= $ x (x - y)$
($x$ is the common factor)
7 (b).
Given expression is-
$\sin^{2} \theta - \sin\theta \cos\theta$
= $ \sin\theta (\sin\theta- \cos\theta)$
($\sin\theta$ is the common factor)