Mary took 8 tests in science and received the following scores: 87,60,76,92,63,91,88,75

Answer:

[tex] x = \dfrac{-\log 7}{\log 7 - \log 2} [/tex]

Step-by-step explanation:

[tex] 2^x = 7^{x + 1} [/tex]

Take the log of both sides.

[tex] \log 2^x = \log 7^{x + 1} [/tex]

Use properties of log.

[tex] x \log 2 = (x + 1) \log 7 [/tex]

[tex] x \log 2 = x \log 7 + \log 7 [/tex]

[tex] x \log 2 - x \log 7 = \log 7 [/tex]

[tex] x(\log 2 - \log 7) = \log 7 [/tex]

[tex] x = \dfrac{\log 7}{\log 2 - \log 7} [/tex]

[tex] x = \dfrac{\log 7}{-(\log 7 - \log 2)} [/tex]

[tex] x = \dfrac{-\log 7}{\log 7 - \log 2} [/tex]

Answer:

(a) [tex]\frac{1}{7}[/tex]

(b) [tex]\frac{4}{7}[/tex]

(c) [tex]\frac{5}{7}[/tex]

Step-by-step explanation:

Probability (P) of an event is the likelihood that the event will occur. It is given by;

P = number of favourable outcomes ÷ total number of events in the sample space.

Given letters of cards:

A B C D E F G H J

∴ Total number of events in sample space is actually the number of cards which is 7

If a card is picked at random;

(a) the probability P(F), that it is labelled F is given by;

P(F) = number of favourable outcomes ÷ total number of events in the sample space.

The number of favourable outcomes for picking an F = 1 since there is only one card labelled with F.

∴ P(F) = 1 ÷ 7

=> P(F) = [tex]\frac{1}{7}[/tex]

(b) the probability P(N), that it is labelled with a letter in her name JADE is given by;

P(N) = P(J) + P(A) + P(D) + P(E)

Where;

P(J) = Probability that it is labelled J

P(A) = Probability that it is labelled A

P(D) = Probability that it is labelled D

P(E) = Probability that it is labelled E

P(J) = [tex]\frac{1}{7}[/tex]

P(A) = [tex]\frac{1}{7}[/tex]

P(D) = [tex]\frac{1}{7}[/tex]

P(E) = [tex]\frac{1}{7}[/tex]

∴ P(N) = [tex]\frac{1}{7}[/tex] + [tex]\frac{1}{7}[/tex] + [tex]\frac{1}{7}[/tex] + [tex]\frac{1}{7}[/tex]

∴ P(N) = [tex]\frac{4}{7}[/tex]

(c) the probability P(S), that it is labelled with a letter that has at least one line of symmetry is;

P(S) = P(A) + P(B) + P(C) + P(D) + P(E) + P(H)

Where;

P(A) = Probability that it is labelled A

P(B) = Probability that it is labelled B

P(C) = Probability that it is labelled C

P(D) = Probability that it is labelled D

P(E) = Probability that it is labelled E

P(H) = Probability that it is labelled H

Cards with letters A, B, C, D, E and H are selected because these letters have at least one line of symmetry. A line of symmetry is a line that cuts an object into two identical halves. Letters A, B, C, D, E and H can each be cut into two identical halves.

P(A) = [tex]\frac{1}{7}[/tex]

P(B) = [tex]\frac{1}{7}[/tex]

P(C) = [tex]\frac{1}{7}[/tex]

P(D) = [tex]\frac{1}{7}[/tex]

P(E) = [tex]\frac{1}{7}[/tex]

P(H) = [tex]\frac{1}{7}[/tex]

∴ P(S) = [tex]\frac{1}{7}[/tex] + [tex]\frac{1}{7}[/tex] + [tex]\frac{1}{7}[/tex] + [tex]\frac{1}{7}[/tex] + [tex]\frac{1}{7}[/tex]

∴ P(S) = [tex]\frac{5}{7}[/tex]

Answer:

4th option

Step-by-step explanation:

in geometric sequences the number is multiplied or divided by same number continuously

in the 4th option we can see that the number 1 is multiplied by 4 continuously so the correct answer would be that.

Answer: one solution.

Step-by-step explanation:

[tex]\dfrac{2}{3} x-4=12-2x\\\\\dfrac{2}{3} x+2x=12+4\\\\2\dfrac{2}{3} x=16\\\\\dfrac{8}{3} x=16\\\\8x=16 \cdot 3\\\\8x=48\\\\x=\dfrac{48}{8} =6[/tex]

This equation has one solution:  x = 6.

Answer:

1/2 or 0.5 hours

Step-by-step explanation:

r = time for repairman to fix one pair of shoes.

a = time for assistant to fix one pair of shoes.

a = r×1.5

x×r + y×a = 6

x = number of pairs of shoes repaired by repairman.

y = number of pairs of shoes repaired by assistant.

x+y = 10

y = 10-x

x = y×1.5 (based on the a/r ratio : as the assistant needs 1.5 times longer, the repairman will have repaired 1.5 times more pair of shoes in the same time)

y = 10 - y×1.5

y + y×1.5 = 10

2.5×y = 10

y = 4

=> x = 6

6×r + 4×r×1.5 = 6

6×r + 6×r = 6

12×r = 6

r = 6/12 = 1/2 or 0.5 hours

Answer:

degrees of 5 or greater

Step-by-step explanation:

peaks counted are 5

Answer:

you nepali me nepali all are nepalese nepalese are only unintelligent

Answer:

part a-24 questions

part b-2 or 3 more questions

Step-by-step explanation:

part a-to find the number, change the percent into a decimal (.75) and multiply (24)

part b-first find how many questions need to be right to get 80% (.80 times 32=25.6). then subtract by how many he would get with a 75% (25.6-24=about 2 to 3 more questions, rounded 2)

The solution to the equation 30x² - 28x + 6 = 0 is x = 3/5 and x = 1/3 option (B) and (E) are correct.

Any equation of the form [tex]\rm ax^2+bx+c=0[/tex] where x is variable and a, b, and c are any real numbers where a ≠ 0 is called a quadratic equation.

As we know, the formula for the roots of the quadratic equation is given by:

[tex]\rm x = \dfrac{-b \pm\sqrt{b^2-4ac}}{2a}[/tex]

We have a quadratic equation:

30x² - 28x + 6 = 0

a = 30, b = -28, and c = 6

Plug the values in the formula:

[tex]\rm x = \dfrac{-(-28) \pm\sqrt{(-28)^2-4(30)(6)}}{2a}[/tex]

After solving:

x = 3/5 or x = 1/3

Thus, the solution to the equation 30x² - 28x + 6 = 0 is x = 3/5 and x = 1/3 option (B) and (E) are correct.

Learn more about quadratic equations here:

brainly.com/question/2263981

#SPJ1

Answer:

31°,59°

Step-by-step explanation:

csc (2x+9)=sec(3x+26)

1/sin(2x+9)=1/cos (3x+26)

sin (2x+9)=cos(3x+26)

cos (90-2x-9)=cos(3x+26)

90=3x+26+2x+9

5x+35=90

5x=90-35=55

x=55/5=11

2x+9=2×11+9=31°

3x+26=3×11+26=59°

Answer:

Step-by-step explanation:

I am using trig identities and the formula for the difference of the cos of 2 angles to solve this. I'll do the steps one at a time. It's super tricky. First I'm just going to work on simplifying the sec² part and then I'll introduce the sin²(x) - sin⁴(x) when I need it. Beginning with the identity for the difference of the cos of 2 angles, knowing that sec²(x) = [tex]\frac{1}{cos^2(x)}[/tex]:

[tex]sec^2(\frac{\pi}{2}-x)=\frac{1}{cos^2(\frac{\pi}{2}-x )}[/tex] and expand that using the formula for the difference:

[tex]\frac{1}{cos(\frac{\pi}{2}-x)cos(\frac{\pi}{2}-x) }=[/tex] [tex]\frac{1}{(cos\frac{\pi}{2}cos(x)+sin\frac{\pi}{2}sin(x))(cos\frac{\pi}{2}cos(x)+sin\frac{\pi}{2}sin(x)) }[/tex] and all of that simplifies down to

[tex]\frac{1}{(0cos(x)+1sin(x))(0cos(x)+1sin(x))}[/tex] which simplifies further to

[tex]\frac{1}{(sin(x))(sin(x))}=\frac{1}{sin^2(x)}[/tex] Now we'll bring in the other term. This is what we have now:

[tex]\frac{1}{sin^2(x)}(\frac{sin^2(x)-sin^4(x)}{1})[/tex] and distribute in to get:

[tex]\frac{sin^2(x)}{sin^2(x)}-\frac{sin^4(x)}{sin^2(x)}[/tex] which simplifies to

[tex]1-sin^2(x)[/tex] and that, finally, simplifies down to a simple

[tex]cos^2(x)[/tex]

Answer:

28

Step-by-step explanation:

2[3*5]-2

2*15-2

30-2

28

Answer:

cos(2π/35)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Pre-Calculus

Step-by-step explanation:

Step 1: Define

Identify

cos(π/5)cos(π/7) + sin(π/5)sin(π/7)

Step 2: Simplify

Answer:

5r³ - 34r² + 44r - 16

Step-by-step explanation:

[tex] \small \sf \: (5r − 4)(r² − 6r + 4)[/tex]

use the distributive property

5r × (r² − 6r + 4) - 4× (r² − 6r + 4)

5r³ - 30r² + 20r - 4r² + 24r - 16

combine like terms

5r³ - 30r² - 4r² + 20r + 24r - 16

5r³ - 34r² + 44r - 16

The product of the expressions is 5r^3 - 34r^2 + 44r - 16

The product of two expression is done by multiplying the expressions

The product expression is given as:

[tex](5r - 4)(r^2 - 6r + 4)[/tex]

Expand the expression

[tex]5r^3 - 30r^2 + 20r - 4r^2 + 24r - 16[/tex]

Collect like terms

[tex]5r^3 - 30r^2 - 4r^2 + 20r + 24r - 16[/tex]

Evaluate the like terms

[tex]5r^3 - 34r^2 + 44r - 16[/tex]

Hence, the product of the expressions is 5r^3 - 34r^2 + 44r - 16

Read more about product at:

https://brainly.com/question/4344214

Answer:

8 : 27

Step-by-step explanation:

The ratio of the volumes is the ratio of the scale factor cubed

2^3 : 3^3

8 : 27

Answer:

8 : 27

Step-by-step explanation:

Given 2 similar cylinders with height ratio = a : b , then

ratio of volumes = a³ : b³

Here height ratio = 2 : 3

ratio of volumes = 2³ : 3³ = 8 : 27

Answer:

The distance between X and Z is approximately 95.99 km

Step-by-step explanation:

(For Diagram Please Find in Attachment)

The distance of Y from X = 85 km

The bearing of Y from X = 190°

The bearing of Z from Y = 140°  

The bearing of Z from X = 180°

Now,  

∠YZX = 180° - (130° + 10°) = 40°

(85 km)/sin(40°) = XZ/(sin(130°))

XZ = sin(130°) × (85 km)/sin(30°) ≈ 95.99 km

The distance between X and Z ≈ 95.99 km

Answer:

A. [tex](-1,-2)[/tex]

Step-by-step explanation:

Hope this helps you.

( -4, 1 ) and ( 2 , -5 )

Now,

mid point = ( 2 - 4 )/2 , ( -5 + 1 )/2

= ( -2 /2 ) , ( -4 /2)

= ( - 1, - 2 )

A ( - 1, - 2 )

I hope it's help you...

Mark me as brainliest...

Answer:

82.9+38.6=121.5 miles far away.

Answer:

first one

Step-by-step explanation:

a + b = c

subtract a from both sides

b = c - a

or

c - a = b

[tex]\longrightarrow{\green{ a. \: c - a = b }}[/tex] 

[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\red{:}}}}}[/tex]

[tex]a + b = c[/tex]

[tex]⇢ b = c - a[/tex]

[tex]⇢ c - a = b[/tex]

[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{❦}}}}}[/tex]

Answer:

50 crates

Step-by-step explanation:

First we need to convert 2 tons into pounds; 2 short tons = 4000 pounds, so the greatest number of crates that can be loaded onto the elevator is 4000 Hope this helps >:D

Answer:

angle IGH = 50 degree

Step-by-step explanation:

triangle GHI is an isosceles triangle because it's two sides are equal.

if angle I is 50 degree then angle G is also 50 degree becasue in isosceles triangle the base angles are equal.

Answer:

# of 20cent stamps = 8

Step-by-step explanation:

Let the  number 20cent stamps be = x

Let the number 60 cents stamps be = y

Total number of stamps => 20 = x + y ----------- ( 1 )

Total cost of the stamps = 8.80

That is, 0.20x + 0.60y = 8.80 ------------- ( 2 )

      ( 2 ) => 20x + 60y = 880

            => x + 3y = 44

           =>  x = 44 - 3y

Substitute x in  ( 1 ) => x  +  y = 20

                                 44 - 3y + y = 20

                                     - 2y = 20 - 44

                                     - 2y = - 24

                                       2y = 24

                                       y = 12

Substitute y = 12 in  ( 1 ) => x + y = 20

                                         x + 12 = 20

                                            x = 8

( 3 × 5 ) + ( 2 × 4 ) =

15 + 8 = $ 23

Answer:

Step-by-step explanation:

Use the standard form equation along with 3 of the coordinates from the table. I used (-1, 2.5), (0, 5), and (1, 8.5). Begin always with the coordinate where you have a 0:

[tex]5=a(0)^2+b(0)+c[/tex] and we get immediately that c = 5. We can use that value as move forward with the next coordinate pair.

[tex]8.5=a(1)^2+b(1)+5[/tex] and

8.5 = a + b + 5 and

3.5 = a + b Hold that thought while we come up with the second equation for this system.

[tex]2.5=a(-1)^2+b(-1)+5[/tex] and

2.5 = a - b + 5 and

-2.5 = a - b  Now solve this system using the method of eliination:

  a  +  b  =  3.5

+ a  -  b  = -2.5

so

2a = 1 and a = 1/2 Now we can plug that in and solve for b:

a + b = 3.5 becomes

1/2 + b = 3.5 so

b = 3 and the equation is

[tex]y=\frac{1}{2}x^2+3x+5[/tex]

Answer:

3.78 × [tex]10^{2}[/tex] = 378

Step-by-step explanation:

Answer:

The passenger's luggage has an excess weight of 2 kg, which is 10% of the maximum weight.

Step-by-step explanation:

First, we need to find the weight (W) of the 4 bags:

[tex] W = 3.5 kg + 15 kg + 2 kg + 1.5 kg = 22 kg [/tex]

Now, knowing that the maximum allowed (M) is 20 kg the excess weight of the luggage is:

[tex] W_{e} = W - M = 22 kg - 20 kg = 2 kg [/tex]

We can express the excess weight in percentage as follows:

[tex] \% W_{e} = \frac{W_{e}}{M} \times 100 = \frac{2 kg}{20 kg}\times 100 = 10 \% [/tex]  

Therefore, the passenger's luggage has an excess weight of 2 kg, which is 10% of the maximum weight.          

I hope it helps you!