Answer pls pls pls pls

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

Bring the fraction a/a-4 to a denominator of 16-a^2

Which is the correct first step in finding the area of the base of a cylinder with a volume of 26x cubic meters and a height of 6.5 meters? v=bh 6.5=b(26x) v=bh v=26pi+(6.5) v=bh v=26pi(6.5) v=bh 26pi=b(6.5)