Answer:
12
Step-by-step explanation:
469.75-10.75 =
459 ÷ 38.25 =
12
With the $10 gift card, Jose can buy at most 8 songs
x(the number of songs) less than or equal to 8
Let the distance of the first part of the race be x, and that of the second part, 15 - x, then
x/8 + (15 - x)/20 = 1.125
5x + 2(15 - x) = 40 x 1.125
5x + 30 - 2x = 45
3x = 45 - 30 = 15
x = 15/3 = 5
Therefore, the distance of the first part of the race is 5 miles and the time is 5/8 = 0.625 hours or 37.5 minutes
The distance of the second part of the race is 15 - 5 = 10 miles and the time is 1.125 - 0.625 = 0.5 hours or 30 minutes.
Answer:
5 miles.
Step-by-step explanation:
Consider the question: Jinghua hiked 4 1/2 miles through the woods in 2 1/4 hours. She hiked the return trip at the same average rate but by a different route taking 2 1/2 hours. How many miles did Jinghua hike on the return trip ?
First of all, we will find Jinghua's speed using given information as:

Convert mixed fractions into improper fractions:



Using property
:


We know that distance is equal to the product of speed and time.

Since we have been given that Jingua hiked the return trip at the same average rate, so distance covered by her on return trip would be speed (2 miles her hour) times given time (2 1/2 hours).



Therefore, Jingua hiked 5 miles on her return trip.
Answer:
Part 1)
See Below.
Part 2)

Step-by-step explanation:
Part 1)
The linear approximation <em>L</em> for a function <em>f</em> at the point <em>x</em> = <em>a</em> is given by:

We want to verify that the expression:

Is the linear approximation for the function:

At <em>x</em> = 0.
So, find f'(x). We can use the chain rule:

Simplify. Hence:

Then the slope of the linear approximation at <em>x</em> = 0 will be:

And the value of the function at <em>x</em> = 0 is:

Thus, the linear approximation will be:

Hence verified.
Part B)
We want to determine the values of <em>x</em> for which the linear approximation <em>L</em> is accurate to within 0.1.
In other words:

By definition:

Therefore:

We can solve this by using a graphing calculator. Please refer to the graph shown below.
We can see that the inequality is true (i.e. the graph is between <em>y</em> = 0.1 and <em>y</em> = -0.1) for <em>x</em> values between -0.179 and -0.178 as well as -0.010 and 0.012.
In interval notation:
