So we have the system of equations:

equation (1)

equation (2)
To use substitution, we are going to solve for one variable in one of our equations, and then we are going to replace that value in the other equation:
Solving for

in equation (2):



equation (3)
Replacing equation (3) in equation (1):






equation (4)
Replacing equation (4) in equation (3):



We can conclude that the solution of our system of equations is <span>
(7/5, 21/10)</span>
Answer: Period = 4
Amplitude = 3
<u>Step-by-step explanation:</u>
Period is the interval of one "cycle" before the pattern repeats.
If you notice that when x = 0, y = -4.
When does the pattern repeat (reach -4 again)?
Answer: when x = 4.
So the interval of one "cycle" is 4 units --> Period = 4.

It would be D, because to be a function, a set of ordered pairs cannot have the same x value. The y value can be the same though.
(5,6), (8,6), (9,6)
As you can see, all of the x values are different, so it is a function.
Answer: x = - 2√5, √5/3
Step-by-step explantion
3 √ 5 x 2 + 25 x − 10 √ 5 = 0 35x2+25x−105=0
⇒ 3√5x2 + 30x – 5x – 10√5 = 0
⇒ 3√5x(x + 2√5) – 5(x + 2√5) = 0
⇒ (x + 2√5)(3√5x – 5) = 0
x = - 2√5, √5/3
Answer: 6.05 units
Step-by-step explanation:
<em>Correct question is:</em>
<em>A cone with radius 3 units is shown below. Its volume is 57 cubic units. Find the height of the cone. Use 3.14 for pi and round your final answer to the nearest hundredth.</em>
Hi, to answer this question we have to apply the next formula:
Volume of a cone = 1/3 x π x radius^2 x height
Replacing with the values given:
57 = 1/3x 3.14 x (3)^2 (h)
Solving for h
57 = 1/3 x 3.14 x 9 (h)
57 =9.42h
57/9.42 =h
h= 6.05 units
Feel free to ask for more if needed or if you did not understand something.