Answer:
Center: 
Radius: 
Step-by-step explanation:
It is necessary to remember that the Equation of the circle in Center-radius form, is:

Where the center of the circle is at the point (h, k) and the radius is "r".
Then, given the following equation of the circle:

We can notice that it is written in Center-radius form. Then we can identify that:

Therefore the center is:

And the radius is:

Answer:
We are asked to find the duration of entire race. As Rachel finished of the race in 6 hours, so of x will be equal to 6. Therefore, the duration of entire race was 8 hours.
( i looked this up but that is the answer i dont take any credit for this answer)
First, isolate the x:
5x-2x= 2-3
Then solve!
3x= -1
x= -1/3
Hope this helps!
Answer:
Step-by-step explanation:
x= money earned per hour working as a cashier.
y=money earned per hour working delivering newspapers.
We propose the following system of equations:
5x + 4y =77
6x + 3y=78
We solve the system by reduction method:
-6*(5x+4y=77) ⇒ -30x-24y=-462
5*(6x+3y=78)⇒ 30x+15y=390
---------------------------
-9y=-72 ⇒ y=-72 /-9=8
Now, we get the value of "x" replacing the value of "y" by "8" in any part of the equation above.
5x + 4(8)=77
5x+32=77
5x=77-32
5x=45
x=45/5=9
therefore;
money earned per hour working as a cashier= $9/ hour
money earned per hour working delivering newspapers=$8/hour
If Simone has 20 bills, then:
1/5 of 20 = 4 [hundreds]
1/4 of 20 = 5 [fifites]
1/10 of 20 = 2 [$20s]
4 * 100 + 5 * 50 + 2 * 20 = 400 + 250 + 40 = 690 [out of $780]
4 + 5 + 2 = 11 [out of 20 bills]
So now we can easily find out she had 9 bills of tens - because 20 - 11 = 9 or because (780 - 690) ÷ 10 = 90 ÷ 10 = 9.