we have that
Let
A -----> total tension in tugboat A
B -----> total tension in tugboat B
we have
Ax+Bx=8,000 ------> equation 1
Ax=Acos(18)
Bx=Bcos(18)
substitute
Acos(18)+Bcos(18)=8,000 -----> equation 2
and
Ay=By
Asin(18)=Bsin(18)
A=B
therefore
Acos(18)+Bcos(18)=8,000 ------> Acos(18)+Acos(18)=8,000
2Acos(18)=8,000
A=8,000/(2cos(18))
A=4,205.8 pounds
answer is
total tension in tugboat A is 4,205.8 pounds
total tension in tugboat B is 4,205.8 pounds