<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>
C = 3b+2d is the same as 3b+2d = C
Let's isolate d. To do this, we first need to subtract 3b from both sides
3b+2d = C
3b+2d-3b = C-3b
2d = C-3b
Then divide both sides by 2
2d = C-3b
2d/2 = (C-3b)/2
d = (C-3b)/2
Take note of the parenthesis as they are very important. We want to divide ALL of C-3b over 2. We don't want to just divide -3b over 2.
The answer choices you have aren't 100% clear but I have a feeling your teacher meant to say d = (C-3b)/2 instead of d = C-3b/2 for choice A
If that assumption is correct, then the answer is choice A.
(-4,-2)
You just plug in the numbers from the ordered pair, into your equation. Remember, the formula for ordered pairs are (x,y). :)
Answer:
7
Step-by-step explanation:
280=40t/40
t=7
Answer:
£2.80
Step-by-step explanation:
7%= 7/100
(7/100)*40=2.8
