Answer:

Step-by-step explanation:
A road is perpendicular to a highway leading to a farmhouse d miles away.
An automobile passes through the point of intersection with a constant speed
= r mph
Let x be the distance of automobile from the point of intersection and distance between the automobile and farmhouse is 'h' miles.
Then by Pythagoras theorem,
h² = d² + x²
By taking derivative on both the sides of the equation,




When automobile is 30 miles past the intersection,
For x = 30

Since 
Therefore,


Answer:
The y-value of the vertex is 
Step-by-step explanation:
we know that
The equation of a vertical parabola into vertex form is equal to

where
(h,k) is the vertex of the parabola
In this problem we have
-----> this a vertical parabola open upward
Convert to vertex form
Group terms that contain the same variable, and move the constant to the opposite side of the equation

Factor the leading coefficient

Complete the square. Remember to balance the equation by adding the same constants to each side


Rewrite as perfect squares


The vertex is the point 
The y-value of the vertex is 
First, convert 5 hours into minutes:
5 hours 60 min
------------ * --------------- = 300 min
1 1 hr
Next, find the unit rate in m/min:
9673.6 m
--------------- = 32.24 m/min
300 min
Now find the distance you can walk in 70 minutes at this rate:
32.24 m
------------- * 70 min = 2247 meters (answer)
1 min
You could walk 2247 meters (to the nearest meter) in 70 minutes.
Answer:
AX : XB as AB : AC
AX = 5
XB = 4
AC = 6
AB = x
Step-by-step explanation:
5 : 4 as to x : 6
ratios can also be written as fractions...
5/4 = x/6 ..now we have a proportion...so we cross multiply
(4)(x) = (5)(6)
4x = 30
x = 30/4
x = 15/2 <==== AB = 15/2
Answer:
The expanded form of 6,398 is 6000 + 300 + 90 + 8