Ask question

Ask question

All categories

pickupchik [31]

2 years ago

11

Serena worked 18 hours last week for a landscaper. She worked 1/3 of those hours planting flowers and 1/2 of those hours mowing

lawns. How many hours did Serena work planting flowers?

1 answer:

Flura [38]2 years ago

5 0

Answer: 6 hours

Step-by-step explanation:

18 ÷ 3 = 6 hours :)

You might be interested in

a concrete company is pouring concrete into a triangular form as the center of a new playground. the foreman measures the triang

Gemiola [76]

Answer:

Equilateral type of Triangle is created.

Step-by-step explanation:

Incenter: It is a point of intersection of angle bisector of three angles of a triangle.

Circumcenter: It is a point of intersection of perpendicular bisector of three sides of a triangle.

For an Equilateral Triangle points incenter and circumcenter must coincide (same). Hence the type is Equilateral Triangle

4 0

2 years ago

Five molecules have speeds of 2.8, 3.2, 5.8, 7.3, and 7.4 m/s. their root-mean-square speed is closest to

frosja888 [35]

The complete question in the attached figure

we know that

the root mean square speed, is the square root of the average (mean) of all of the square of the speeds of individual particles in a gas.

step 1
find the square of the speeds of individual particles
2.8²----> 7.84
3.2²---->10.24
5.8²----> 33.64
7.3²----> 53.29
7.4²---> 54.76
average=[7.84+10.24+33.64+53.29+54.76]/5-----> 159.77/5----> 31.954

step 2
find the square root of the average
√31.954=5.65

therefore

the answer is
the option b) 5.7 m/s

7 0

2 years ago

A sociologist studying the difference in ages between husbands and wives obtained a random sample of 55 married couples. The mea

zalisa [80]

Answer:

2.1/√55

Step-by-step explanation:

simga divided by sample size

8 0

2 years ago

Suppose that a system of linear equations has 3×5 augmented matrix whose 5th column is a pivot column. Is the system consistent?

Anon25 [30]

No, the system is inconsistent.

Step-by-step explanation:

If the last column is a pivot column, then that row gives an equation that looks something like 0x+0y+0z=1 , meaning , 0=1. Clearly, this is false.

So, the system of linear equations is inconsistent.

7 0

2 years ago

Given the general identity tan X =sin X/cos X , which equation relating the acute angles, A and C, of a right ∆ABC is true?

irakobra [83]

First, note that $m\angle A+m\angle C=90^{\circ}.$ Then

$m\angle A=90^{\circ}-m\angle C \text{ and } m\angle C=90^{\circ}-m\angle A.$

Consider all options:

A.

$\tan A=\dfrac{\sin A}{\sin C}$

By the definition,

$\tan A=\dfrac{BC}{AB},\\ \\\sin A=\dfrac{BC}{AC},\\ \\\sin C=\dfrac{AB}{AC}.$

Now

$\dfrac{\sin A}{\sin C}=\dfrac{\dfrac{BC}{AC}}{\dfrac{AB}{AC}}=\dfrac{BC}{AB}=\tan A.$

Option A is true.

B.

$\cos A=\dfrac{\tan (90^{\circ}-A)}{\sin (90^{\circ}-C)}.$

By the definition,

$\cos A=\dfrac{AB}{AC},\\ \\\tan (90^{\circ}-A)=\dfrac{\sin(90^{\circ}-A)}{\cos(90^{\circ}-A)}=\dfrac{\sin C}{\cos C}=\dfrac{\dfrac{AB}{AC}}{\dfrac{BC}{AC}}=\dfrac{AB}{BC},\\ \\\sin (90^{\circ}-C)=\sin A=\dfrac{BC}{AC}.$

Then

$\dfrac{\tan (90^{\circ}-A)}{\sin (90^{\circ}-C)}=\dfrac{\dfrac{AB}{BC}}{\dfrac{BC}{AC}}=\dfrac{AB\cdot AC}{BC^2}\neq \dfrac{AB}{AC}.$

Option B is false.

3.

$\sin C = \dfrac{\cos A}{\tan C}.$

By the definition,

$\sin C=\dfrac{AB}{AC},\\ \\\cos A=\dfrac{AB}{AC},\\ \\\tan C=\dfrac{AB}{BC}.$

Now

$\dfrac{\cos A}{\tan C}=\dfrac{\dfrac{AB}{AC}}{\dfrac{AB}{BC}}=\dfrac{BC}{AC}\neq \sin C.$

Option C is false.

D.

$\cos A=\tan C.$

By the definition,

$\cos A=\dfrac{AB}{AC},\\ \\\tan C=\dfrac{AB}{BC}.$

As you can see $\cos A\neq \tan C$ and option D is not true.

E.

$\sin C = \dfrac{\cos(90^{\circ}-C)}{\tan A}.$

By the definition,

$\sin C=\dfrac{AB}{AC},\\ \\\cos (90^{\circ}-C)=\cos A=\dfrac{AB}{AC},\\ \\\tan A=\dfrac{BC}{AB}.$

Then

$\dfrac{\cos(90^{\circ}-C)}{\tan A}=\dfrac{\dfrac{AB}{AC}}{\dfrac{BC}{AB}}=\dfrac{AB^2}{AC\cdot BC}\neq \sin C.$

This option is false.

8 0

2 years ago

Read 2 more answers