The word "equation" defines that an expression must have an <em><u>equal sign.</u></em><em> </em>This means that the equation is <em><u>y = x.</u></em> The variable 'y' represents <em><u>the distance Michael has climbed.</u></em>The variable 'x' represents<em><u>the time mike hiked.</u></em>
=> y = x
=> 400 ft = 2 hours
=> 200 ft = 2/2 hours
=> <u>200 ft = 1 hour</u>
<u>Hence, 200 ft = 1 hour models the relationship between the time Michael hikes, x, and the distance he climbs, y.</u>