# Question 1. Factorize pqr + qr 2 − pr 2 − r 3

**Question 1. Factorize **

Factorization methods —

**Solution: **

To factorize this expression we see that qr is common between first two terms and is common between the last two terms. So this expression can be dealt by taking commons out from respective pair of terms;

If we put brackets again for the sake of understanding we see it as;

Now we can see that (p+r) is common here – taking it out, we get;

So, these are two factors of the expression uptill now;

Butif seen closely in the second factor viz , r is again a common to be found — take it out – we get;

**So, finally r , (p+r) and (q-r) are three factors of the given expression.**