Simplify the following
I need help how to set it up and why you got the answer

Answer:
√(6-3t)²-(4+t)² = 2√2t²-11t+5
Step-by-step explanation:
Expand (6-3t)²-(4+t)² : 8t²-44t+20
=√8t²-44t+20
Factor 8t²-44t=+20: 4(2t²-11t+5)
=√4(2t²-11t+5)
=√4√2t²-11t+5
√4=2
So the answer is 2√2t²-11t+5. Hope this helps you.