Question

Help me to factorise the following expressions

1.tu+tv+su+sv
2.mn+3m+kn+3k​

Answer 1

1. (t + s)(u + v).

2. (m + k)(n + 3).

Explanation:

1. tu+tv+su+sv

Note that t is common in the first 2 terms and s is common to the last 2.

= t(u + v) + s(u + v)

Now u + v is common so we have:

(t + s)(u + v).

2. mn+3m+kn+3k​

= m(n + 3) + k(n + 3)

= (m + k)(n + 3).