Answer:
(x + 4)^2 + (y - 8)^2 = 81
or
(x + 4)^2 + (y - 8)^2 = 9^2 depending on how your teacher wants it written.
Step-by-step explanation:
The standard form for a circle is
(x + h)^2 + (y + k)^2 = r^2
r is the radius.
You are given the diameter
r = d/2
r = 18/2
r = 9
So you already have the right hand side of the equation
(x + h)^2 + (y + k)^2 = 9*2
(x + h)^2 + (y + k)^2 = 81
You basically have h and k as well. They come from the center point.
h = 4
k = - 8
So the equation of the circle (and the answer) is
(x + 4)^2 + (y - 8)^2 = 81
One question remains. Why do the x and y values change signs? If you know what the distance formula is, then what you are finding is the distance r of all points on the circle from the center of the circle.
It is the distance formula that is actually the formula for the circle.
<span>the correct answer is -4 - 0.144337567 i</span>
The answer is C. 1,000,000
Answer:
180 coins
Explanation:
N = number of nickels (no nickels spent)
D = number of dimes initially saved
D' = number of dimes left after spending
1) N = D + 43
2) D' = D - 17
3) N = 2*D' = 2*(D - 17)
Set equations 1) and 3) equal to each other and solve for D:
D + 43 = 2*(D - 17)
D + 43 = 2*D - 34
D = 43 + 34 = 77
N = D + 43 = 77 + 43 = 120 nickels left
D' = D - 17 = 77 - 17 = 60 dimes left
Total coins left = 120 + 60 = 180 coins (I hope this is not too confusing for you)
The answer is y= 3/4x - 4.
