What is the solution to the equation f(x)=g(x) ?

i graphed it but there were two spots the lines intersected at.

Beth makes batches of bluberry muffins and banna muffins. each batchis 6 muffins. she makes 2.5 batches of bluberry muffins. how many batches of bananna muffins should beth make if she wants to have a total of 60 muffins?

Math it's appreciated. (picture provided)

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?