Can someone help me please

Answer:

160 chemistry books and 80 history books

Step-by-step explanation:

C=chemistry books sold, H=history books sold

C=2H

C+H=240, 3H=240, H=80, C=160

Answer:

C

Step-by-step explanation:

Given

[tex]\frac{x^2-16}{(x-16)(x+4)}[/tex]

The numerator is a difference of squares

x² - 16 = (x - 4)(x + 4)

= [tex]\frac{(x-4)(x+4)}{(x-16)(x+4) }[/tex] ← cancel the common factor (x + 4) on numerator/ denominator

= [tex]\frac{x-4}{x-16}[/tex] → C

Answer:

26 sqrt(5) + 2 sqrt(10)

Step-by-step explanation:

2 sqrt(5) *(13+sqrt(2))

Distribute

26 sqrt(5) + 2 sqrt(10)

Answer:

[tex]26\sqrt5 +2 \sqrt10[/tex]

Step-by-step explanation:

Answer:

the time taken for the 15 people to drink 155 pints is 20.67 min.

Step-by-step explanation:

Given;

10 people took 5 mins to drink 25 pints of water

[tex]The \ rate\ for \ 10 \ people = \frac{25 \ pints }{5 \ mins} = 5 \ \frac{pints}{\min} \\\\The \ rate \ for \ 1 \ person = \frac{5}{10} \ \frac{pints}{\min} = 0.5 \ \frac{pints}{\min} \\\\The \ rate \ for \ 15 \ people = 15( 0.5 \ \frac{pints}{\min} )= 7.5 \ \frac{pints}{\min} \\\\Time \ taken \ for \ the \ 15 \ people \ to \ drink \ 155 \ pints = \frac{155 \ pints}{7.5 \ pints/ \min} \\\\= 20.67 \min[/tex]

Therefore, the time taken for the 15 people to drink 155 pints is 20.67 min.

The best function that models the data is f(x) = log StartFraction 1 Over x EndFraction, x not-equals 0

Find the table attached below

From the table shown,  we can see that when   x = 1/10, f(x) = 1

Similarly when x = 1/100, f(x) = 2

According to the law of logarithm, we can say that:

Log 10 = 1

Log 100 = 2 etc..

Recall that f(x) = 1 when x = 1/10, this means that;

F(x) = log 10

F(x) = log(1/1/10))

F(x) = log(1/x) since x = 1/10

Similarly if f(x) = 2 when x = 1/100

F(x) = log 100

F(x) = log(1/1/100))

F(x) = log(1/x) since x = 1/100 in this case

On a general note, we can conclude that f(x) = 1/x where x is not equal to zero.

Learn more function models at https://brainly.com/question/11989600

Answer:

A

Step-by-step explanation:

The person above said so

f (x) = StartFraction 1 Over x EndFraction, x not-equals 0

Look in the images it is solved.

Answer:

Step-by-step explanation:

On first day , the video was viewed = 320 times .

We are given that Each day since then, the number of views was 25% more than the day before. This means the likes are increasing 1.25 per day .

So, this situation forms G.P.

Where common ratio r = 1.25

First term = f(1) = 320

Formula of nth term in G.P. =

So, nth term of the given situation :

Where f(n) denotes the number of views on nth day .

So, the number of views Vera's video got on the nth day =

Step-by-step explanation:

Answer:

8 sides (octagon)

Step-by-step explanation:

sum of exterior angles is always 360º

360 / 45 = 8 sides

Answer:

8 sides

Step-by-step explanation:

If all the angles of the polygon are the same, divide the angle by 360 and u get the answer.

Answer:

43.49

Step-by-step explanation:

let his normal hourly rate be x

16x+7x/2=848

39x/2=848

x=848 ÷ 39/2

=43.48717

Answer:

1/144

Step-by-step explanation: I presume..

And recall something from Algebra...

I hope it helps...

Square it

And reverse it because of the negative

It is a fraction

Answer:

[tex] = { \sf{ \frac{1}{ 144 } }}[/tex]

Step-by-step explanation:

[tex] = { \tt{ \frac{1}{ {12}^{2} } }} = \frac{1}{144} [/tex]

Answer:

70

Step-by-step explanation:

we have the angle of vertex in the isosceles triangle = 180-2*bottom coner= 180-65/2=50

3 angles in the equilateral triangle are equal to 60

we have 50 + 60 +h =the angle of PQR =180

h=70

Answer: h = 70°

In the triangle with Angle R = 65

It is a isoceles triangle as two sides are equal

So base angles will be equall too

Then the third angle will which is the q one will be

65+65+q = 180

q = 180 - 130

q = 50

In the other triangle with all sides equal will be equilateral triangle which means all angles equal = 60

So

Now ATQ

60 + 50 + h = 180

h = 180 - 110 (Angles on a straight line adds upto 180)

h = 70

Must click thanks and mark brainliest

Answer:

ratio of Sophia's sweets to Isabel's sweets is

13:8

Answer:

you first have to find the number of sweets that sophia got.by subtracting the total number of sweets minus the number of sweets that isabel got which will be

42-16=26

therefore the ratio will be

16:26

8:13

I hope this helps

Answer:

slope = - [tex]\frac{8}{5}[/tex]

Step-by-step explanation:

Calculate the slope m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (23, - 30) and (x₂, y₂ ) = (- 7, 18)

m = [tex]\frac{18-(-30)}{-7-23}[/tex] = [tex]\frac{18+30}{-30}[/tex] = [tex]\frac{48}{-30}[/tex] = - [tex]\frac{8}{5}[/tex]

Answer:

The possible approximate frequencies of the guitar string are 516.82 Hz and 508.82 Hz

Step-by-step explanation:

The given period of the tuning fork, T₁ = 1.95 × 10⁻³ s

The number of beats in 6.0 s = 24 beats

Therefore, the beat frequency, [tex]f_{beat}[/tex] = 4 beats per second = 4 Hz

Let f₁ represent the frequency of the tuning fork, and let f₂ represent the frequency of the guitar string, we have;

f₁ = 1/T₁ = 1/(1.95 × 10⁻³) ≈ 512.82 Hz

We have;

[tex]f_{beat} = \left | f_2 - f_1 \right |[/tex]

[tex]\pm f_{beat} = f_2 - f_1[/tex]

Therefore, we get;

[tex]4 \, Hz= \left | f_2 - 512.82 \, Hz \right |[/tex]

f₂ - 512.82 = ± 4

∴ f₂ = 512.82 ± 4

The possible frequencies of the guitar string,  f₂ ≈ 516.82 Hz or f₂ ≈ 508.82 Hz

Answer:

An electric company calculates a person's monthly bill from the number of kilowatt-hours (kWh), x, used, x 200 The function b(ar) = { 0.102, 0.15(x - 200) +20, 200 determines the bill How much is the bill for a person who uses 800 kWh in a month?

Answer:

a) x=3

b) x=4.5

Step-by-step explanation:

2(5x – 3) = 24

10x-6=24

10x=30

x=3

5(2x + 1) = 50

10x+5=50

10x=45

x=4.5

[tex] \sf3m + 12 = 15 \\ \sf3m = 15 - 12 \\ \sf3m = 3 \\ \sf \: m = \frac{3}{3} \\ \sf \: m \: = \underline{ \bf \: 1}[/tex]

-> Just move all the numbers from the left side to the right side until only the variable is left. Then you can solve the equation & find the required value.

3 m+ 12 = 15

⇔3 m=  3

⇔m=  1

Answer:

(2,1)

Step-by-step explanation:

2x - 2y = 2

5x + 2y = 12

again just add them in this case

7x = 14

x = 2

4 - 2y = 2

-2y = -2

y = 1

Answer:

x + y + z.

Step-by-step explanation:

x² + y² + 2xy - z²

= (x + y)^2 - z^2

This is the difference between 2 squares so the factors are:

(x + y + z) and (a + y - z).

Answer: The factors are (x+y+z) and (x+y-z)

In other words, it factors to (x+y+z)*(x+y-z)

=====================================================

Work Shown:

[tex]x^2 + y^2 + 2xy - z^2\\\\(x^2 + 2xy + y^2) - z^2\\\\(x+y)^2 - z^2\\\\(x+y+z)(x+y-z)\\\\[/tex]

Notes:

Answer:

cot a = 3 3/7

or, cot a = 24/7

or, tan a = 7/24

So,

cos a = 24/25

tan a = 7/24

Answered by GAUTHMATH

Answer:

for every minute it will cost 3 dollars

Step-by-step explanation:

c(x)=3x+2.00

The cost to get in the taxi is 2 dollars

The slope is 3

3x means that for every minute it will cost 3 dollars

Answer:

(1/9)^2 x 1/3

Step-by-step explanation:

1/243

=> 1 / 3 x 3 x 3 x 3 x 3

=> 1 / 9 x 9 x 3

=> (1/9)^2 x 1/3

Answer:

3.25 minutes

Step-by-step explanation:

3.25 minutes per green light x 24 = 78

the yellow light is a given, hence 6 cars pass through

78 + 6 = 84 cars

Answer: width:60.2 cm

Length: 64.2 cm

Step-by-step explanation:

Given

The area of the rectangle is [tex]3990\ cm^2[/tex]

Width of the rectangle is [tex]x\ cm[/tex]

Length of the rectangle is [tex]x+4\ cm[/tex]

Area of the rectangle is the product of length and width

[tex]\therefore 3990=(x+4)x\\\Rightarrow 3990=x^2+4x\\\Rightarrow x^2+4x-3990=0\\\Rightarrow x=60.198\ or\ -65.198\ cm\\\text{Neglecting negative term}\\\Rightarrow x=60.198\approx 60.2\ cm[/tex]

Width of the rectangle is [tex]60.2\ cm[/tex]

Length of the rectangle is [tex]60.2+4=64.2\ cm[/tex]

Answer:

d 28.8cm2

Step-by-step explanation:

1/2BH

1/2() 12.8() 4.5

28.8

Answer:

x ≈ 94.4

Step-by-step explanation:

Using the tangent ratio in the right triangle

tan58° = [tex]\frac{LM}{KL}[/tex] = [tex]\frac{x}{59}[/tex] ( multiply both sides by 59 )

59 × tan58° = x , then

x ≈ 94.4 ( to the nearest tenth )

Answer:

240 cubic cm

Step-by-step explanation:

Volume of a cone = 1/3(nr^2h)

volume of a cylinder = nr^2h

n = 22/7

r = radius

The volume of a cone is 1/3 that of a cylinder

to determine the volume of the cylinder with the same parameters as a cylinder, multiply the volume of the cone by 3

80 x 3 = 240 cubic cm

Answer:

I have no clue sorry my bad bro