This is really confusing me:
simplify so that your answers contain only positive exponents.

  see below

Step-by-step explanation:

For simplifying expressions of this sort, there are four rules of exponents that come into play;

__

I find it convenient to eliminate the fractions by adding the exponents, then rewrite any negative exponents as denominator factors.

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet