Respuesta :
Everything you need to do for this question is everything you do to one side you do it to the other
Answer:
missing factor=t+3
Step-by-step explanation:
t²+3s+3t+st
=t²+st+3s+3t
=t(t+s)+3(s+t)
=(t+s)(t+3)
=(t+3)(t+s)
