Step-by-step explanation:
since y=6x
by substitution
-5x+ 2 (6x)= -42
-5x+ 12x=-42
7x= - 42
divide both sides by 7
x= 6
y=6x
y =6*6
y=36
Answer: A
You’re basically adding m - 2 nine times
So it’s 9m - 18
Or 9m - 9(2)
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:
s = 4/21
Step-by-step explanation:
Move all terms not containing s to the right side of the equation, then solve.