Speed of the plane: 250 mph
Speed of the wind: 50 mph
Explanation:
Let p = the speed of the plane
and w = the speed of the wind
It takes the plane 3 hours to go 600 miles when against the headwind and 2 hours to go 600 miles with the headwind. So we set up a system of equations.
600
m
i
3
h
r
=
p
−
w
600
m
i
2
h
r
=
p
+
w
Solving for the left sides we get:
200mph = p - w
300mph = p + w
Now solve for one variable in either equation. I'll solve for x in the first equation:
200mph = p - w
Add w to both sides:
p = 200mph + w
Now we can substitute the x that we found in the first equation into the second equation so we can solve for w:
300mph = (200mph + w) + w
Combine like terms:
300mph = 200mph + 2w
Subtract 200mph on both sides:
100mph = 2w
Divide by 2:
50mph = w
So the speed of the wind is 50mph.
Now plug the value we just found back in to either equation to find the speed of the plane, I'll plug it into the first equation:
200mph = p - 50mph
Add 50mph on both sides:
250mph = p
So the speed of the plane in still air is 250mph.
Answer:
AC = 3.72 units
Angles:
A = 132.6°
C = 27.4°
Step-by-step explanation:
AC² = 5² + 8² - 2(5)(8)cos(20)
AC² = 13.82459034
AC = 3.718143399
3.718143399/sin20 = 8/sinA
sinA = 0.7358944647
A = 180 - 47.38285134
A = 132.6171487
3.718143399/sin20 = 5/sinC
sinC = 0.4599340405
C = 27.38285134
The missing number is the square-root of the constant term on the left-hand-side, which equals sqrt(1/16)=1/sqrt(16)=1/4.
Check:
(x+1/4)^2=x^2+2*(1/4)x+(1/4)^2=x^2+x/2+1/16. ok
Answer: x= 1/4
Answer:
Some 224 people were in favor of the expansion.
Step-by-step explanation:
Given that, according to the recent poll, 22 1/4% of the people polled said that they approved of the city plan to expand the library, if 1004 people was polled, to determine how many were in favor of the expansion should be done the following calculation:
1/4 = 0.25
100 = 1004
22.25 = X
1004 x 22.25 / 100 = X
223.39 = X
Thus, some 224 people were in favor of the expansion.
