Answer:
Slope = - 8
y-intercept = - 4
Step-by-step explanation:
<span>Find the wind speed and the plane's airspeed.
:
Let s = speed of the plane in still air
Let w = speed of the wind
then
(s-w) = plane speed against the wind
and
(s+w) = plane speed with the wind
:
Change 3 3/8 hrs to 3.375 hrs
:
The trips there and back are equal distance, (1890 mi) write two distance equations
dist = time * speed
:
3.375(s-w) = 1890
3.0(s + w) = 1890
:
It is convenient that we can simplify both these equations:
divide the 1st by 3.375
divide the 2nd by 3
resulting in two simple equations that can be used for elimination of w
s - w = 560
s + w = 630
----------------adding eliminates w, find s
2s = 1190
s =
s = 595 mph is the plane speed in still air
Find w
595 + w = 630
w = 630 - 595
w = 35 mph is the wind spee</span>
18. s = 5r^2 + 7......making r the subject
s - 7 = 5r^2
(s - 7) / 5 = r^2...by taking the sqrt of both sides, it eliminates the ^2
( sqrt (s-7)/5) = r
19. h = ut - 1/2gt^2....u = 100, t = 1 4/5(or 9/5)...g = 6.4
h = (100)(9/5) - 1/2(6.4)(9/5^2)
h = 180 - 1/2(6.4)(3.24)
h = 180 - 3.2(3.24)
h = 180 - 10.368
h = 169.632 or 169 79/125
20. sorry..do not know this one
<span>x(t-u) = 3t
dividing both sides by (t-u):
So.. </span><span><em>x = 3t/(t-u)</em></span>
