Answer:
The sound level would be at 80 decibels at 1 or 7 number of measures played
Explanation:
Equations with Absolute Values
We have the function s to represent the sound level in decibels:

Where x is the number of measures of the music played.
We are required to find the value of x that makes s=80 decibels. We have to find the equation:

Subtracting 50:


Dividing by 10:


For the absolute value be equal to 3, its argument could be positive or negative:

Or

This leads us to two solutions:

x=7
Or


x=1
The sound level would be at 80 decibels at 1 or 7 number of measures played