Question

Factorise the expression:
$p^2{q}^2-6pqr+9r^2$

(1 mark)

Answer 1

Solution:

Given, the expression is
$p^2{q}^2-6pqr+9r^2.$
The above expression can be written as,
$(pq{)}^2-2(pq\left)\right(3r)+(3r{)}^2$

(0.5 marks)

Now, applying the identity
$(a-b{)}^2=a^2-2ab+b^2$, we get
$(pq-3r{)}^2$
$=(pq-3r)(pq-3r)$

(0.5 marks)