Similarity and Proof Unit activity Course activity:AA, SAS, and SSS criteria for Similar triangles

I'm stuck on these two activities on Plato for geometry, If anyone has done these before please help I am having a very hard time and my anxiety is kicking in. I'm literally crying right now

What are “like terms”? why can we only add like terms?

Which value would be a solution for x in the inequality 47-4x< 7

Acylinder with a base diameter of x units has a volume of jxcubic units which statements about the cylinder are true? check all that apply. the radius of the cylinder is 2 x units. the radius of the cylinder is 2x units. the area of the cylinder's base is 200 square units. the area of the cylinder's base is a square units. the height of the cylinder is 2x units. the height of the cylinder is 4x units. mark this and return save and exit next submit