Volume of a cylinder = π · radius(r)² · height(h)
Since you didn't provide the radius or the height, I am unable to provide a solution to this problem but hopefully you can solve it on your own now that you have the formula.
O.o that so hard but my big sister know how to do it
Elimination Method

If we multiply the equation 3 by (-1) we obtain this:

If we add them we obtain 0, therefore there are infinite solutions. So, let's write it in terms of Z
1. Using the 3rd equation we can obtain X(Y,Z)

2. We can replace this value of X in the 1st and 2nd equations

3. If we simplify:

4. We can obtain Y from this two equations:

5. Now, we need to obtain X(Z). We can replace Y in X(Y,Z)

6. If we simplify, we obtain:

7. In conclusion, we obtain that
(X,Y,Z) =
Given:
Discount = 40%
Sales tax = 7%
To find:
The total cost of levi jeans with an original price of x.
Solution:
Let x be the original price of the jeans. Then the price after 40% discount is




The price after 7% of sales tax.




Therefore, the total cost of the levi jeans with an original price of x is represented by the expression 0.642x.