Answer: 20 mph
Explanation:
Speed is a physical quantity which is equal to the ratio between the distance covered (d) and the time taken (t):
In the first part of the problem, the plane flew a distance of d=400 mi in a time of t=2.5 h. The speed of the plane in this case was the difference between the proper speed of the plane, v, and the speed of the wind, w, since the plane flew opposite to the wind. So we can write:
(1)
During the return trip, the plane flew with a speed (v+w), since the wind was on the tail, and it took 2 hours to cover the same distance:
(2)
So we have two equations with two unknown variables. From (1), we get
Substituting into eq.(2)
So, the speed of the wind was 20 mph.
Answer:
A. I can't quite see the question, but I'm pretty sure it's A
Step-by-step explanation:
Sin(A) = 1/3
Sin^2(A) + Cos^2(A) = 1
(1/3)^2 + cos^2(A) = 1
1/9 + cos^2(A) = 1
cos^2(A) = 1 - 1/9
cos^2(A) = 8/9
cos(A) = √(8/9)
√8 = √(2 * 2 * 2) = 2√2
√9 = 3
cos(A) = 2√2/3
Answer:
160 Pounds
Step-by-step explanation:
2x2-5x-18=0
Two solutions were found :
x = -2
x = 9/2 = 4.500
Step by step solution :
Step 1 :
Equation at the end of step 1 :
(2x2 - 5x) - 18 = 0
Step 2 :
Trying to factor by splitting the middle term
2.1 Factoring 2x2-5x-18
The first term is, 2x2 its coefficient is 2 .
The middle term is, -5x its coefficient is -5 .
The last term, "the constant", is -18
Step-1 : Multiply the coefficient of the first term by the constant 2 • -18 = -36
Step-2 : Find two factors of -36 whose sum equals the coefficient of the middle term, which is -5 .
-36 + 1 = -35
-18 + 2 = -16
-12 + 3 = -9
-9 + 4 = -5 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -9 and 4
2x2 - 9x + 4x - 18
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (2x-9)
Add up the last 2 terms, pulling out common factors :
2 • (2x-9)
Step-5 : Add up the four terms of step 4 :
(x+2) • (2x-9)
Which is the desired factorization
Equation at the end of step 2 :
(2x - 9) • (x + 2) = 0
Step 3 :
Theory - Roots of a product :
3.1 A product of several terms equals zero.
When a product of two or more terms equals zero, then at least one of the terms must be zero.
We shall now solve each term = 0 separately
In other words, we are going to solve as many equations as there are terms in the product
Any solution of term = 0 solves product = 0 as well.
Answer:
k = 3
Step-by-step explanation:
0 • 3 = 0
1 • 3 = 3
2 • 3 = 6
3 • 3 = 9
4 • 3 = 12
Notice the x value times 3 is the y value. Therefore, k is 3. Let me know if I got anything wrong. I hope this helps!
