All categories

2 years ago

Marta walked at 3.9 miles per hour for 0.72 hours. How far did she walk

Mathematics

2 answers:

blsea [12.9K]2 years ago

8 0

Answer: 2.808 miles

Step-by-step explanation:

Given: Marta walked in 1 hour = 3.9 miles (rate of walking per hour)

The number of hours Marts walked = 0.72 hour

To find the distance walked by Marta we need to multiply the distance traveled in 1 hour (rate of walking per hour) by 0.72 hour, we get

The distance walked by Marta= $3.9\times0.72$ miles

Therefore, the distance walked by Marta=2.808 miles

Kobotan [32]2 years ago

6 0

3.9 miles 0.72 hours -------------- X ---------------- 1 hour 1 multiply across, 3.9x0.72=2.808 miles

You might be interested in

rectangle abcd is similar to rectangle pqrs. given ab=14 cm, BC=8cm and pq=21cm, calculate the length of QR

weqwewe [10]

QR =12 because you set up a proportion 21/14=x/8 then cross multiply and get 14x=168 then you divide and get 12

6 0

2 years ago

Which shows the four-term polynomial and factored form of x2 + 6x-27?

blsea [12.9K]

Answer:

0x2+9x-3x-27 6x-27

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

Verify the given linear approximation at a = 0. Then determine the values of x for which the linear approximation is accurate to

nikklg [1K]

Answer:

Part 1)

See Below.

Part 2)

$\displaystyle (-0.179, -0.178) \cup (-0.010, 0.012)$

Step-by-step explanation:

Part 1)

The linear approximation L for a function f at the point x = a is given by:

$\displaystyle L \approx f'(a)(x-a) + f(a)$

We want to verify that the expression:

$1-36x$

Is the linear approximation for the function:

$\displaystyle f(x) = \frac{1}{(1+9x)^4}$

At x = 0.

So, find f'(x). We can use the chain rule:

$\displaystyle f'(x) = -4(1+9x)^{-4-1}\cdot (9)$

Simplify. Hence:

$\displaystyle f'(x) = -\frac{36}{(1+9x)^{5}}$

Then the slope of the linear approximation at x = 0 will be:

$\displaystyle f'(1) = -\frac{36}{(1+9(0))^5} = -36$

And the value of the function at x = 0 is:

$\displaystyle f(0) = \frac{1}{(1+9(0))^4} = 1$

Thus, the linear approximation will be:

$\displaystyle L = (-36)(x-(0)) + 1 = 1 - 36x$

Hence verified.

Part B)

We want to determine the values of x for which the linear approximation L is accurate to within 0.1.

In other words:

$\displaystyle \left| f(x) - L(x) \right | \leq 0.1$

By definition:

$\displaystyle -0.1\leq f(x) - L(x) \leq 0.1$

Therefore:

$\displaystyle -0.1 \leq \left(\frac{1}{(1+9x)^4} \right) - (1-36x) \leq 0.1$

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 y = 0.1 and y = -0.1) for x values between -0.179 and -0.178 as well as -0.010 and 0.012.

In interval notation:

$\displaystyle (-0.179, -0.178) \cup (-0.010, 0.012)$

4 0

2 years ago

Sebastian was in a hotel lobby and took the elevator up 7 floors to his room. Then he took the elevator down 9 floors to the par

Crank

Answer:

Sebastian didn't interpret the numbers correctly (See explanation)

Step-by-step explanation:

If you go up an elevator, you are gaining floors, so the number is positive.

If you go down an elevator, you are losing floors, so the number is positive.

Looking at the statement, he went 7 floors up to his room, then 9 floors down to the parking garage this can be represented as $7 - 9$ , since the 7 is positive and the 9 is negative.

Sebastian described the movement as $9 + -7$ , which is wrong - 9 should be -9 and -7 should be 7.

Hope this helped!

3 0

2 years ago

Read 2 more answers

Abraham throws a ball from a point 40 m above the ground. The height of the ball from the ground level after ‘t' seconds is defi

Minchanka [31]

Answer:

8.899s

Solve: -5t^+40t+40

7 0

2 years ago