Ask question

Ask question

All categories

3 years ago

10

Which of the following expressions is a correct interpretation of the expression 2-(-7)

1 answer:

Arte-miy333 [17]3 years ago

7 0

Answer:

B

Step-by-step explanation:

Because you are subtracting a negative number from a positive number, the two negatives will cancel each other out and it will move to the right.

You might be interested in

Can you solve 5a please greatly appreciated.

timurjin [86]

Part I)
The module of vector AB is given by:
lABl = root ((- 3) ^ 2 + (4) ^ 2)
lABl = root (9 + 16)
lABl = root (25)
lABl = 5

Part (ii)
The module of the EF vector is given by:
lEFl = root ((5) ^ 2 + (e) ^ 2)
We have to:
lEFl = 3lABl
Thus:
root ((5) ^ 2 + (e) ^ 2) = 3 * (5)
root ((5) ^ 2 + (e) ^ 2) = 15
Clearing e have:
(5) ^ 2 + (e) ^ 2 = 15 ^ 2
(e) ^ 2 = 15 ^ 2 - 5 ^ 2
e = root (200)
e = root (2 * 100)
e = 10 * root (2)

3 0

3 years ago

A 15-ft ladder leans against a wall. The lower end of the ladder is being pulled away from the wall at the rate of 1.5 ft/sec. L

Aleks [24]

Answer:

The top of the ladder is sliding down at a rate of 2 feet per second.

Step-by-step explanation:

Refer the image for the diagram. Consider $\Delta ABC$ as right angle triangle. Values of length of one side and hypotenuse is given. Value of another side is not known. So applying Pythagoras theorem,

$\left ( AB \right )^{2}+\left ( BC \right )^{2}=\left ( AC \right )^{2}$

From the given data, $L=15\:ft=AC$ , $y=9\:ft=AB$ and $x=BC$

Substituting the values,

$\therefore \left ( 9 \right )^{2}+\left ( x \right )^{2}=\left ( 15 \right )^{2}$

$\therefore 81+x^{2}=225$

$\therefore x^{2}=225-81$

$\therefore x^{2}=144$

$\therefore \sqrt{x^{2}}=\sqrt{144}$

$\therefore x=\pm 12$

Since length can never be negative, so $x= 12$ .

Now to calculate $\dfrac{dy}{dt}$ again consider following equation,

$\left ( y \right )^{2}+\left ( x \right )^{2}=\left ( l \right )^{2}$

Differentiate both sides of the equation with respect to t,

$\dfrac{d}{dt}\left(y^2+x^2\right)=\dfrac{d}{dt}\left(l^2\right)$

Applying sum rule of derivative,

$\dfrac{d}{dt}\left(y^2\right)+\dfrac{d}{dt}\left(x^2\right)=\dfrac{d}{dt}\left(l^2\right)$

$\dfrac{d}{dt}\left(y^2\right)+\dfrac{d}{dt}\left(x^2\right)=\dfrac{d}{dt}\left(225\right)$

Applying power rule of derivative,

$2y\dfrac{dy}{dt}+2x\dfrac{dx}{dt}=0$

Simplifying,

$y\dfrac{dy}{dt}+x\dfrac{dx}{dt}=0$

Substituting the values,

$9\dfrac{dy}{dt}+12\times1.5=0$

$9\dfrac{dy}{dt}+18=0$

Subtracting both sides by 18,

$9\dfrac{dy}{dt}=-18$

Dividing both sides by 9,

$\dfrac{dy}{dt}= - 2$

Here, negative indicates that the ladder is sliding in downward direction.

$\therefore \dfrac{dy}{dt}= 2\:\dfrac{ft}{sec}$

7 0

3 years ago

Target sells a watch for $99 and offers a 15% discount. Walmart sells the same watch for $59 and offers a 10% discount. Which st

joja [24]

Answer:

Walmart

Step-by-step explanation:

Target: 15% of 99 = $14.85 If you reduce $99 by $14.85 you get $84.15

Walmart: 10% of 59 = $5.90 If you reduce $59 by $5.90 you get $53.10

5 0

3 years ago

If there are 9 showings of a film at the science at a total of 486 people saw the same film the same number of people at each sh

a_sh-v [17]

54 people saw the film at each showing

6 0

3 years ago

Astore pays $927.40 for a water heater and marks the price up by 5%. What is the new price?

Slav-nsk [51]

Answer:

$973.77

Step-by-step explanation:

$927.40 = 100%

New price = 100% + 5%

New price = 105% of 927.40

105% of 927.40 = 1.05(927.40)

1.05(927.40) = 973.77

-Chetan K

8 0

3 years ago