<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>
In case of plane, for y intercept, x and z are o .
So we will get
4(0)+5y-0=20
5y=20
Dividing both sides by 5
y = 4
So the y intercept is (0,4,0).
In second question, x intercept is 1, y intercept is -1 and z intercept is 2 .
So the correct option is the third equation , that is x-y+2z=4 .
1.
a.) 2q + 5r
2(7) + 5(-2)
14 - 10 = 4
b.) 3(p + 6) + q + r Plug in the numbers
3(5 + 6) + 7 - 2 Solve inside the parentheses first
3(11) + 7 - 2
33 + 5 = 38
2.
a.) m(3m + 4n)
2(3(2) + 4(3))
2(6 + 12)
2(18) = 36
b.) n²(m + p²)
(3)²(2 + (-5)²)
9(2 + 25)
9(27) = 243
c.) 3m(8 + n) + n²
3(2) (8 + 3) + 3²
6(11) + 9
66 + 9 = 75
The 90% confidence interval is (70 - 4, 70 + 4). The margin of error is 4%.
