All categories

3 years ago

Can someone help me with this?

Mathematics

1 answer:

oksian1 [2.3K]3 years ago

5 0

Answer:

85 hours
10 2/3 ≈ 11 days

Step-by-step explanation:

We can treat this as a units conversion problem. Each multiplier is a fraction that has the same value in the numerator as the denominator, but expresses that value with different units. We choose to cancel units we don't want, and replace them with units we do want. Ultimately, we're evaluating the expression ...

time = quantity/rate

(4 mi²) × (640 ac/mi²) × (5 min)/(2.5 ac) × (1 h)/(60 min)

= (4·640·5)/(2.5·60) h = 85 1/3 h

It will take about 85 hours to plant the farm.

At 8 hours per day, that is (85 1/3)/(8) = 10 2/3 days.

It will take about 11 days to plant the farm.

You might be interested in

Please dont ignore, Need help!!! Use the law of sines/cosines to find..

Ket [755]

Answer:

16. Angle C is approximately 13.0 degrees.

17. The length of segment BC is approximately 45.0.

18. Angle B is approximately 26.0 degrees.

15. The length of segment DF "e" is approximately 12.9.

Step-by-step explanation:

By the law of sine, the sine of interior angles of a triangle are proportional to the length of the side opposite to that angle.

For triangle ABC:

$\sin{A} = \sin{103\textdegree{}}$ ,
The opposite side of angle A $a = BC = 26$ ,
The angle C is to be found, and
The length of the side opposite to angle C $c = AB = 6$ .

$\displaystyle \frac{\sin{C}}{\sin{A}} = \frac{c}{a}$ .

$\displaystyle \sin{C} = \frac{c}{a}\cdot \sin{A} = \frac{6}{26}\times \sin{103\textdegree}$ .

$\displaystyle C = \sin^{-1}{(\sin{C}}) = \sin^{-1}{\left(\frac{c}{a}\cdot \sin{A}\right)} = \sin^{-1}{\left(\frac{6}{26}\times \sin{103\textdegree}}\right)} = 13.0\textdegree{}$ .

Note that the inverse sine function here $\sin^{-1}()$ is also known as arcsin.

By the law of cosine,

$c^{2} = a^{2} + b^{2} - 2\;a\cdot b\cdot \cos{C}$ ,

where

$a$ , $b$ , and $c$ are the lengths of sides of triangle ABC, and
$\cos{C}$ is the cosine of angle C.

For triangle ABC:

$b = 21$ ,
$c = 30$ ,
The length of $a$ (segment BC) is to be found, and
The cosine of angle A is $\cos{123\textdegree}$ .

Therefore, replace C in the equation with A, and the law of cosine will become:

$a^{2} = b^{2} + c^{2} - 2\;b\cdot c\cdot \cos{A}$ .

$\displaystyle \begin{aligned}a &= \sqrt{b^{2} + c^{2} - 2\;b\cdot c\cdot \cos{A}}\\&=\sqrt{21^{2} + 30^{2} - 2\times 21\times 30 \times \cos{123\textdegree}}\\&=45.0 \end{aligned}$ .

For triangle ABC:

$a = 14$ ,
$b = 9$ ,
$c = 6$ , and
Angle B is to be found.

Start by finding the cosine of angle B. Apply the law of cosine.

$b^{2} = a^{2} + c^{2} - 2\;a\cdot c\cdot \cos{B}$ .

$\displaystyle \cos{B} = \frac{a^{2} + c^{2} - b^{2}}{2\;a\cdot c}$ .

$\displaystyle B = \cos^{-1}{\left(\frac{a^{2} + c^{2} - b^{2}}{2\;a\cdot c}\right)} = \cos^{-1}{\left(\frac{14^{2} + 6^{2} - 9^{2}}{2\times 14\times 6}\right)} = 26.0\textdegree$ .

For triangle DEF:

The length of segment DF is to be found,
The length of segment EF is 9,
The sine of angle E is $\sin{64\textdegree}}$ , and
The sine of angle D is $\sin{39\textdegree}$ .

Apply the law of sine:

$\displaystyle \frac{DF}{EF} = \frac{\sin{E}}{\sin{D}}$

$\displaystyle DF = \frac{\sin{E}}{\sin{D}}\cdot EF = \frac{\sin{64\textdegree}}{39\textdegree} \times 9 = 12.9$ .

7 0

3 years ago

Please Help Me!

nikitadnepr [17]

Answer:

Step-by-step explanation:

4*15=60 60*3.14=188.4 188.4*1/3= 62.8 rounded that would be 63

3 0

4 years ago

Which decimal is equivalent to 8/45?

Vilka [71]

Answer:

.1<u>777</u><u>.</u><u>.</u><u>.</u><u> </u><u>(</u><u>7</u><u> </u><u>is </u><u>repeating)</u>

6 0

3 years ago

13. Distributive Property<br> 3(x - 1) = 3x - ?

goblinko [34]

Answer:

$\huge\boxed{3x-3}$

Step-by-step explanation:

$3(x-1)=\\\\\text{Distribute: }\left \{ {{3*x=3x} \atop {3*-1=-3}} \right.\\\\3(x-1)=\boxed{3x-3}$

8 0

4 years ago

Read 2 more answers

Please help for eleven points

Arlecino [84]

C: B:

3 0

6 9

9 18

12 27

All you had to do was plug in the value for c or b and solve. You can tell this is most likely correct because you see patterns for both variables. C is going up by threes, while b is going up by nines.

3 0

3 years ago