(2x−2)−(2x−4) simplify the equation

How do you use the elimination method for this question? explain, because i really want to understand!

What is the total surface area of the square pyramid

Acommunity group is building a garden on a rectangular lot of land. the lot measures 5x by 10x and the garden will be circular with a radius of 3x. how much of the land will be left over after the garden is built? a. 41 pi x^2 b. x^2 (50 - 9 pi) c. x^2 (50 - 3 pi) d. 41x^2