Answer: 
a=-3
b=-9
Step-by-step explanation:

I cant tell if this is french or spanish but please translate so we can try to help you
Answer:
hope this helpful
Step-by-step explanation:
isosceles right
because A light ray incident at 90° at the first face emerges at the same angle. The diagram shows five isosceles right-angled prisms. A light ray incident at 90° at the first face emerges at the same angle with the normal from the last face.
4
Step-by-step explanation:
8/5(put 8 as numerator becuz we need to find all x from 5/8) x 2 1/2=4