Express 243 as power of 3 explain

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Which of the following circles have their centers in the third quadrant? check all that apply.