What makes this part of author's argument effective?

Afruit stand has to decide what to charge for their produce. they decide to charge \$5.30$5.30dollar sign, 5, point, 30 for 111 apple and 111 orange. they also plan to charge \$14$14dollar sign, 14 for 222 apples and 222 oranges. we put this information into a system of linear equations. can we find a unique price for an apple and an orange?

Which words best describes the speakers?

Add -ment to the following word. you may use a dictionary