Answer:
answer = 12.87 km/h
Step-by-step explanation:
Given
Ship A is sailing east at 25 km/h = 
ship B is sailing north at 20 km/h =
here x and y are the sailing at t = 4 : 00 pm for ship A and B respectively
so we get x = 4 ×25 =100 km/h
y = 4× 20 = 80 km/h
let z is the distance between the ships, we need to find 
at t = 4 hr
At noon, ship A is 130 km west of ship B (12:00 pm)
so equation will be
derivative first equation w . r. to t we get
![\frac{dz}{dt} =\frac{1}{z}[(x -130)\frac{dx}{dt} +y\frac{dy}{dt}]](https://tex.z-dn.net/?f=%5Cfrac%7Bdz%7D%7Bdt%7D%20%3D%5Cfrac%7B1%7D%7Bz%7D%5B%28x%20-130%29%5Cfrac%7Bdx%7D%7Bdt%7D%20%2By%5Cfrac%7Bdy%7D%7Bdt%7D%5D)
Solve for m.
Add 7 to both sides to get 3m=15
Then divide by sides by 3 to get m=5.
The final answer is m=5.
$25! Think about it, to get $15.90 as your discounted price, the unknown number must be multiplied by 60% to get $15.90. If you wanna find the original price, do the opposite! What is $15.90 divided by .6? $25!
Answer:
To find increase/decrease, divide the starting number by the ending number.
<u>40 to 20</u>
20 ÷ 40 = 0.5
0.5 can be represented by 50%.
<u>20 to 40</u>
40 ÷ 20 = 2
2 can be represented by 200%. This is why decreasing 40 to 20 is a 200% increase. In the wording, it says it's a 100% increase. That would be 20 plus 20 times 1 (which is the same as 100%) which is 40.
