Answer:
John ski down the mountain is 1285.37 feet.
Step-by-step explanation:
Given : John is skiing on a mountain with an altitude of 1200 feet. The angle of depression is 21.
To find : About how far does John ski down the mountain ?
Solution :
We draw a rough image of the question for easier understanding.
Refer the attached figure below.
According to question,
Let AB be the height of mountain i.e. AB=1200 feet
The angle of depression is 21 i.e. 
We have to find how far does John ski down the mountain i.e. AC = ?
Using trigonometric,




Therefore, John ski down the mountain is 1285.37 feet.
9y - 5x = 20
or, (9y - 5x) / 20 = 1
or, 9/20 y - 1/4 x = 1
compare with x/a + y/b = 1
you'll get
x intercept (a) = -4
y intercept (b) = 20/9
Q 1. 1,776 and 1,396
q 2. 1,250
q 3. 3.5 million