The distance between the Sun and each planet in our solar system varies because the planets travel in elliptical (oval) orbits around the Sun rather than completely circular ones. Here is a table of the average distance and the variation in the distance for the five innermost planets in our solar system:

Average Distance and Variation
Planet Name Average Distance Variation
Mercury 36.0 million miles 7.39 million miles
Venus 67.2 million miles 0.43 million miles
Earth 93.0 million miles 1.55 million miles
Mars 142 million miles 13.2 million miles
Jupiter 484 million miles 23.2 million miles

"Average distance" means the mean distance that planet is from the sun over the course of its orbit, and "variation" means how far it varies from that mean. For example, if a planet had an average distance of 5 miles and a variation of one mile, it would have distances between 4 and 6 miles at different times.

a) Write and solve an inequality to represent the range of distances that can occur between the Sun and one of the planets from the table (your choice). Show your steps/process.

b) Why is this best represented as an inequality rather than an equation? Explain in at least 3 sentences.