Question 1 Redone

$(\neg P\vee Q),(P\vee \neg Q),(P\vee Q),(R\vee S\vee T\vee U)$

Rule	Partial Assignment	(1)	(2)	(3)	(4)
Initial	$\varnothing$	|	|	|	|
Pure Literal $R$	$R$	|	|	|	✅
Branch $\neg P$	$R,\neg P$	✅	$\neg Q$	$Q$	✅
Conflict	$R,\neg P$	✅	❌	❌	✅
Backtrack $P$	$R,P$	$Q$	✅	✅	✅
Unit Clause $Q$	$R,P,Q$	✅	✅	✅	✅

Hence satisfying assignment is $R:=\top ,P:=\top ,Q:=\top$.