Answer:
(x, y) =(-1, - 1)
Step-by-step explanation:
-Substitute the value of x
-solve the equation
-Substitute the value of y
-check the possible solution
-check solution
-simplify
The first equation has no solution
The picture shows all the work I did, the reason I took a pic is because it is a little hard to explain by text, but I hope this helped you!
Answer:
C. 
Step-by-step explanation:
Iterative geometric sequence:

Recursive geometric sequence:

The equations are very similar and you only really need to rearrange it. The factor (2/3) and the first term (9) are given, so you can write the iterative equation:

And so the answer is C.
Answer:
The portion of the volume of the cup that is filled with water is 
Step-by-step explanation:
step 1
Find the volume of the paper water cup
The volume of the cone is equal to

we have


substitute


step 2
If the cup is filled with water to half its height, find out what portion of the volume of the cup is filled with water
Remember that
If two figures are similar, then the ratio of its volumes is equal to the scale factor elevated to the cube
In this problem the similar cone has half the height of the complete cone
so
The scale factor is equal to 1/2
therefore
The volume of the cup that is filled with water is equal to the volume of the complete cup by the scale factor elevated to the cube

therefore
The portion of the volume of the cup that is filled with water is
