Answer:
99/100
Step-by-step explanation:
First of all recall that

Now we we will try to apply that formula for
and
.
First rewrite 
Now

What is the question you are trying to ask
Answer:
y=4x and x+4y=12 are perpendicular because they have opposite reciprocal slopes
Step-by-step explanation:
y=4x slope is 4
x+4y=12 slope is -1/4
Answer: $115.50
Step-by-step explanation:
500.5-385 = x
It would be (12,20) or (20,12) I don't know which one