It would be 5300 when rounded
Option B:

Solution:
Given sound level = 120 decibel
To find the intensity of a fire alarm:

where 
Step 1: First divide the decibel level by 10.
120 ÷ 10 = 12
Step 2: Use that value in the exponent of the ratio with base 10.

Step 3: Use that power of twelve to find the intensity in Watts per square meter.


Now, do the cross multiplication,




Option B is the correct answer.
Hence
.
Answer:
Step-by-step explanation:
You would take the points (x1,y1) and add them into the equation y-y1=m(x-x1). In this equation m is the slope and that equals -4
Well since the first expression says 8x(40+7) the answer would be 40 that is missing
Since your splitting 47 into 40 and 7 and multiplying both of them by 8 the answer would be 40