How to model 23 less than 55 on a number line

Write the rational number in lowest terms 99/-15

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?

Jeremy wants to determine the number of solutions for the equation below without actually solving the equation. which method should jeremy use?