<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>
The Sean's number is x. Formulate the equation:
x * 5 : 2 = 30
5x = 30 * 2
5x = 60
x = 60 : 5
x = 12
Answer: the Sean's number is 12.
Given:
A line passes through (1,-2) and is perpendicular to
.
To find:
The equation of that line.
Solution:
We have, equation of perpendicular line.

Slope of this line is



Product of slope of two perpendicular lines is -1.



Now, slope of required line is
and it passes through (1,-2). So, the equation of line is

where, m is slope.





Therefore, the equation of required line is
.
Answer:
3/10
Step-by-step explanation:
4/15+x=17/30
x=17/30-4/15
x=17/30-8/30
x=9/30
simplify
x=3/10