Answer:
1. (t + s)(u + v).
2. (m + k)(n + 3).
Step-by-step 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).
