Many tornadoes fromed in the sky past future or present

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?

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

Haley buys 9 pounds of apples for $3. how many pounds of apples can she buy for $1?