<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>
4 and 15. You can guess and check or use algebra.
Answer:
B) 15/(9+(-9))
Step-by-step explanation:
Be careful of the parentheses because if you just write out 15/9+(-9),
it's technically, saying that 15/9+(-9)=5/3+(-9)=5/3-9, and that's different from what you want to express, mathematically.
Answer:b
Step-by-step explanation:
Isolating means leaving something on one side of the equation. In this situation, one has to subtract the 2t from both sides
