A reflection is a mirror image. Placing the edge of a mirror on the x-axis will form a reflection in the x-axis. This can also be thought of as "folding" over the x-axis.
If the original (parent) function is <span>y = f (x)</span><span>, the <span>reflection over the x-axis </span>is function</span><span> -f (x)</span><span>.</span>
Since there are six groups of student and each group consists of 3 students, therefore, the total number of students is 18. All of them sold 162 balloons. In order to know how many balloons each student sold, we just have to divide 162 by 18 and the answer is 9. Hope this answers your question.