Jaime’s goal is to average at least 280 miles per week for 4 weeks. If T is the total number of miles Jamie will bicycle for 4 weeks, then his goal can be represented symbolically by the inequality:
≥280,or equivalently
T≥4(280). The total number of miles Jamie will bicycle during this time is the sum of the distances he has completed and has yet to complete. Thus
T=240+310+320+x. Substituting this expression into the inequality
T≥4(280) gives
240+310+320+x≥4(280). Therefore, choice D is the correct answer.
Choices A, B, and C are incorrect because they do not correctly capture the relationships between the total number of miles Jaime will ride his bicycle
(240+310+320+x) and the minimum number of miles he is attempting to bicycle for the four weeks
(280+280+280+280)