Answer:
D
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r is the radius
here (h, k) = (- 6, - 8), thus
(x + 6)² + (y + 8)² = r²
The radius is the distance from the centre to a point on the circle
Calculate r using the distance formula
r = √ (x₂ - x₁ )² + (y₂ - y₁ )²
with (x₁, y₁ ) = (- 6, - 8) and (x₂, y₂ ) = (0, 0)
r = 
= 
= 
= 10
Hence
(x + 6)² + (y + 8)² = 100 → D
<span>Answer:
Roma Sherry drove 330 miles from her hometown to Tucson. During her return trip, she was able to increase her speed by 11 mph. If her return trip took 1 hour less time, find her original speed and her speed returning home.
:
Let s = original speed
then
(s+11) = return speed
:
Write a time equation: Time = distance%2Fspeed
:
Original time = return time + 1 hr
330%2Fs = 330%2F%28%28s%2B11%29%29 + 1
:
Multiply equation by s(s+11) and you have:
330(s+11) = 330s + s(s+11)
:
330s + 3630 = 330s + s^2 + 11s
:
0 = 330s - 330s + s^2 + 11s - 3630
:
A quadratic equation:
s^2 + 11s - 3630 = 0
Factor this to:
(s + 66)(s - 55) = 0
Positive solution
s = 55 mph is original speed.
:
Find the time
330/55 = 6 hr, original time
and
330/66 = 5 hrs, faster time; confirms our solution.</span>
Let Edy's money be x.
Lucy: 35% more --- (135/100) x
x + (135/100) x = 206.80
(47/20)x = 206.80
47x = 206.8 x 20
47x =4136
x = 88
Edy saved $88.
Lucy saved (135/100)(88) = $118.80
Answer:
567 Miles
Step-by-step explanation:
