Simplifying makes a algebric expression easily understandable and solvable.
No, when you give someone points for answering your question it takes them from you but when you give someone brainliest it doesn't take the ones you recieved already for some reason
Answer:
The decibel range is 
Step-by-step explanation:
Let
d -----> the decibel level of the music
we know that
The absolute value of the difference of the decibel level of the music and its average, must be less than or equal to 28 decibels
so
The absolute value that represent this problem is

Solve the absolute value
<em>First solution (positive)</em>

Adds 110 both sides


<em>Second solution (negative)</em>

Multiply by -1 both sides

Adds 110 both sides


therefore
The decibel range is

Answer:
PQ = 28 cm
QR = 21 cm
Step-by-step explanation:
PQ = PS + SQ = 16 + 12= 28
QR = QS + SR = 12 + 9 = 21