The first option is correct (-x)
A. 15 × 1 1/2= 15/1 × 3/2= 45/2= 2 2/5
b.15min +1extra minute=16min. × 15 students =240min so no not enough time
I'm going to assume you've learn sin, cos, and tan. To find a you must do:

Once you find a, you can use the Pythagorean Theorem to find b:

Or you can do:

You can find these functions on a scientific calculator. Let me now if you need more help.
Answer:
-64
Step-by-step explanation:512 divided by 2 can be calculated as follows. 512/2 math problems division = 256. Therefore 256 to 2 decimal places= 256. 512/2