Step 1: Write out the information provided in the question.
Number of people attending the meeting is 80.
Let the number of supervisors be x
Since there were four times as many parents as supervisors, then the number of parents will be 4x
Step 2: convert the above information to mathematical equation, the number of people attending the meeting equals to the sum of the parents and the supervisors, thus,
[tex]x+4x=80[/tex]Step 3: Solve the above equation to get the value of x
[tex]\begin{gathered} x+4x=80 \\ 5x=80 \\ \frac{5x}{5}=\frac{80}{5}(\text{divide both side by 5)} \\ x=16 \end{gathered}[/tex]Step 4: Since the number of supervisors equals x which is 16, the number of parents attending the meeting will be 4x which is
[tex]4x\Rightarrow4\times16=64[/tex]Hence, 16 supervisors and 64 parents attended the meeting