<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>
Answer: B
Step-by-step explanation:
Answer:
B. and C.
Step-by-step explanation:
1. Set the polynomial equal to zero:
x² + 5x + 7 = 0
2. Plug the given values of a, b, and c into the quadratic formula:

3. Solve the square root:



4. Simplify the rest:

5. Separate the solutions:

Thus, options B and C are the answers.
hope this helps!
Answer:
2yrs
Step-by-step explanation:
Given parameters:
Amount of interest earned = $40
Principal = $400
Interest rate = 5%
Unknown:
Time taken for the money to be in bank = ?
Solution:
The formula for interest is given as:
I =
Where I is the interest
P is the principal
R is the rate
T is the time
So;
100I = PRT
T =
=
= 2yrs
They are already rounded but 20% and 30% should be correct.