The transformation of y=f(x) to y=f(2x) is a:

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?

The sum of two numbers is 86, and their difference is 20. find the two numbers

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10