Not really good in math need help this is the most points

Imagine a new pasture with grass growing on it. every day after the seeds have germinated, the number of blades of grass in the pasture triples. after 18 days, the entire pasture is completely covered in grass. how many days did it take for the pasture to be one-third covered in grass?

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?

Find the solution(s) to the system of equations. select all that apply y=x^2-1 y=2x-2