Answer:
The rate of sales tax is 6%.
Step-by-step explanation:
First you must subtract 12.50 from 13.25
This brings you to .75
Then, divide .75/12.50 to get 0.06 which is equivalent to 6 percent.
let 1st and 2nd no be x and y respectively
1st case:x=4y
2nd case:x-y=12
substituting the value of x in 2nd case
4y-y=12
3y=12
y=12÷3
y=4
now putting the value of y in 1st case
x=4×4
=16
Answer:

Step-by-step explanation:
Given
Perpendicular to 
Pass through 
Required
Determine the line equation
First, we need to determine the slope of 
An equation is of the form:

Where

In this case:

Next, we determine the slope of the second line.
Since both lines are perpendicular, the second line has a slope of:



Since this line passes through (-2,2); The equation is calculated as thus:

Where

This gives:



Add 2 to both sides


Amounttotal=amount per day times number of days
200=17.1 times d
divide both sides by 17.1
11.695=d
about 12 days