In order to find "r", you need to isolate it. So in order to isolate it, you do the inverse operation. In this case, it would be division because 0.3 is being multiplied by "r". So you divide by 0.3 on both sides to get 7.
Answer: 
Step-by-step explanation:
The formula for calculate the distance between two points is:

In this case, given the points A(4,-6) and B(-4,2), we can identify that, we just need to substitute values into the formula in order to calculate the distance between the given points.
Thierefore, this is (Rounded to the nearest hundred):

In order to find the cost of each CD, you would have to divide $38.04 by 4 CDs and you would get $9.51 as the cost of each CD. If you want to check if your answer is correct, you can either add $9.51 four times to get $38.04 or you can multiply $9.51 x 4 and you should get $38.04 remember that multiplication is always a way to check your answer for division problems and division is always a way to check an answer to your multiplicatiom problems. Just search it up for more info. Hope i helped! :)
3x + 2y = 19
2x + 4y = 24
this would be ur system of equations