Answer:
It is 100. You round the 6 to the 9 which makes the 9 round the 99 which makes it 100.
Seca(1-sina)(seca+tana)=1
Left hand side
=(1-sina) (seca +tana) / cosa
=seca +tana - sinaseca - sinatan / cosa
=seca + tana -tana -(sin^2a/cosa) / cosa
=(1/cosa - sin^2a/cosa) / cosa
= (1-sin^2a / cosa) / cosa
= (1-sin^2a)/ (cos^2a)
=1 (verified)
Answer: -1
2-1=1
1/-3+2
1/-1
=-1