Answer:
r = 225 Mil/h speed of the airplane in still air
Step-by-step explanation:
Then:
d is traveled distance and r the speed of the airplane in still air
so the first equation is for a 4 hours trip
as d = v*t
d = 4 * ( r + 25) (1) the speed of tail wind (25 mil/h)
Second equation the trip back in 5 hours
d = 5 * ( r - 25 ) (2)
So we got a system of two equation and two unknown variables d and
r
We solve it by subtitution
from equation (1) d = 4r + 100
plugging in equation 2
4r + 100 = 5r - 125 ⇒ -r = -225 ⇒ r = 225 Mil/h
And distance is :
d = 4*r + 100 ⇒ d = 4 * ( 225) + 100
d = 900 + 100
d = 1000 miles
X + Y = 180 so X = 122. W = X = 122. Z = Y = 58
Check the picture below
surely you know how much that is.
<h3>2
Answers: Choice B and Choice D</h3>
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Work Shown:
c = price of coat before discount
0.33c = discount = amount you save
c - 0.33c = original price minus discount = final price
c - 0.33c = 1c - 0.33c = (1-0.33)c = 0.67c = final price
In short, c - 0.33c = 0.67c
They are two ways of expressing the same thing.
You can think of it like saying 100% - 33% = 67%
If you save 33%, then you still have to pay the remaining 67% of the original cost.
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Example:
Let's say the coat is $100 before the discount
c = 100
0.33*c = 0.33*100 = 33 dollars is how much you save
c - 0.33c = 100 - 33 = 67 dollars is the final price
0.67c = 0.67*100 = 67 matches with the previous figure above
