Out of 40 students in class 8,20% were absent.How many students were present?​

Answer:

[tex]x = \displaystyle \frac{5 + \sqrt{17}}{2}[/tex].

Step-by-step explanation:

Because [tex]3\, x[/tex] is found in the input to a logarithm function in the original equation, it must be true that [tex]3\, x > 0[/tex]. Therefore, [tex]x > 0[/tex].

Similarly, because [tex](x - 4)[/tex] and [tex](2\, x - 1)[/tex] are two other inputs to the logarithm function in the original equation, they should also be positive. Therefore, [tex]x > 4[/tex].

Let [tex]a[/tex] and [tex]b[/tex] represent two positive numbers (that is: [tex]a > 0[/tex] and [tex]b > 0[/tex].) The following are two properties of logarithm:

[tex]\displaystyle \ln (a) + \ln(b) = \ln\left(a \cdot b\right)[/tex].

[tex]\displaystyle \ln (a) - \ln(b) = \ln\left(\frac{a}{b}\right)[/tex].

Apply these two properties to rewrite the original equation.

Left-hand side of this equation:

[tex]\begin{aligned}&\ln(3\, x) - \ln(x - 4)= \ln\left(\frac{3\, x}{x -4}\right)\end{aligned}[/tex]

Right-hand side of this equation:

[tex]\ln(2\, x- 1) + \ln(3) = \ln\left(3 \left(2\, x - 1\right)\right)[/tex].

Equate these two expressions:

[tex]\begin{aligned}\ln\left(\frac{3\, x}{x -4}\right) = \ln(3(2\, x - 1))\end{aligned}[/tex].

The natural logarithm function [tex]\ln[/tex] is one-to-one for all positive inputs. Therefore, for the equality [tex]\begin{aligned}\ln\left(\frac{3\, x}{x -4}\right) = \ln(3(2\, x - 1))\end{aligned}[/tex] to hold, the two inputs to the logarithm function have to be equal and positive. That is:

[tex]\displaystyle \frac{3\ x}{x - 4} = 3\, (2\, x - 1)[/tex].

Simplify and solve this equation for [tex]x[/tex]:

[tex]x^2 - 5\, x + 2 = 0[/tex].

There are two real (but not rational) solutions to this quadratic equation: [tex]\displaystyle \frac{5 + \sqrt{17}}{2}[/tex] and [tex]\displaystyle \frac{5 - \sqrt{17}}{2}[/tex].

However, the second solution, [tex]\displaystyle \frac{5 - \sqrt{17}}{2}[/tex], is not suitable. The reason is that if [tex]x = \displaystyle \frac{5 - \sqrt{17}}{2}[/tex], then [tex](x - 4)[/tex], one of the inputs to the logarithm function in the original equation, would be smaller than zero. That is not acceptable because the inputs to logarithm functions should be greater than zero.

The only solution that satisfies the requirements would be [tex]\displaystyle \frac{5 + \sqrt{17}}{2}[/tex].

Therefore, [tex]x = \displaystyle \frac{5 + \sqrt{17}}{2}[/tex].

Answer:

497/1000

Step-by-step explanation:

sorry but that's as simplified as it gets

Answer:

Graph (6, 5) and (-6, -3), and then use a ruler (optional), and draw a line between them, and a little after the points.

Step-by-step explanation:

y = 2/3x + 1

Substitute different numbers for x, and find y:

You don't really want to work with fractions, so try to find a number that when multiplied by 2/3, gives you a whole number

x = 6

y = 2/3(6) + 1

y = 12/3 + 1

y = 4 + 1

y = 5

Point: (6, 5)

x = -6

y = 2/3(-6) + 1

y = -12/3 + 1

y = -4 + 1

y = -3

Point: (-6, -3)

Graph these two points, and then use a ruler (optional), and draw a line between them, and a little after the points.

triangel b is a reflection of triangle a the x-axis triangle c

Answer:

x>15/7

Step-by-step explanation:

Answer:

If you are looking for the slope, it equals -6

Step-by-step explanation:

(3,4) (5, -8)

[tex]\frac{4+8}{3-5}[/tex] = [tex]\frac{12}{-2}[/tex] = [tex]\frac{6}{-1}[/tex] = -6

Hey there!

The formula to this equation is: y2 - y1 /x2 - x1

• y2 = -8

• y1 = 4

• x2 = 5

• x1 = 3

EQUATION:

-8 - 4/5 - 3

-8 - 4 = -12

5 - 3 = 2

NEW EQUATION: -12/2

-12/2 = your answer

-12 / 2 = -6 because 2 • -6 = -12

Answer that you’re looking for: -6

Good luck on your assignment and enjoy your day!

~LoveYourselfFirst:)

Guide to REMEMBER :

- Negative & Negative = Positive

- Negative & Positive = Negative

- Positive & Positive = Positive

- Positive & Negative = Negative

Answer:

[tex]\sqrt{8 m^{6} n^{3}}[/tex]

Step-by-step explanation:

Answer:

The conclusion of the scientist should be that the results are statistically significant and that there is a high probability that the mice brains doubled in sizes after watching the videos

Step-by-step explanation:

The complete question is as follows;

A scientist studies the development of brain size in mice, believing that exposure to statistics videos is related to brain development.. After having mice intensively watch statistics videos, the scientist discovers that mice have doubled the size of their brains. After running a statistical test on the difference, the scientist obtained a p-value of .04. What should the scientist conclude, assuming an a=.05?

Solution;

We start by forming the null hypothesis

The null hypothesis H0 here is that;

The mice have not doubled the sizes of their brains after watching the the videos

While the alternative hypothesis H1 is that the mice have double their brain sizes after watching the videos

To know what to conclude, we will need to look at the p-value obtained

The p-value we have here is 0.04 which is less than 0.05 and thus , shows the existence of a strong evidence against the null hypothesis which means we will have to accept the alternative

Hence, the conclusion of the scientist should be that the results are statistically significant and that there is a high probability that the mice brains doubled in sizes after watching the videos

Answer:

I have no idea, sorry

Step-by-step explanation:

Answer:

interest rate is .000951667 and total interest gained is 47.98 and total money in the bank account is 2147.98

Step-by-step explanation:

you have to find the interest rate then multiply it by 1 year then put it to the power of 24. 24 because you have 34 months in 2 years

Answer:a) 20%

Step-by-step explanation: 2× 100/ 8+2

Answer:

20%

Step-by-step explanation:

girls are 80% just so you know

Answer:

the mayor will lose in a close race

Step-by-step explanation:

Answer:

Answer:

16

Step-by-step explanation:

To find the greatest number of students that could be in each row, we need to find their greatest common factor. We can list out their prime factors first.

48: 2 × 2 × 2 × 2 × 3

64: 2 × 2 × 2 × 2 × 2 × 2

Here, their common prime factors are 2 × 2 × 2 × 2 which is 16. Thus, the greatest number of students that could be in each row is 16.

No. of rows in the girls = 48 ÷ 16

                                      = 3

No. of rows in the boys = 64 ÷ 16

                                       = 4

Answer:

Step-by-step explanation:

I believe for this question you need to find the HCF (or GCF you may say) of 48 and 64

HCF - Highest Common Factor

GCF - Greatest common Factor

First, prime factorize 48 and 64 (write them in the product of their prime numbers)

64 = 2 × 2 × 2 × 2 × 2 × 2

48 = 2 × 2 × 2 × 2 × 3

Choose common prime factors (all of them that are common)

on observation, there is 2 × 2 × 2 × 2 common between both of them

which is 16.

So 16 maximum people in each row

Also additional thing, it's fine if some questions were wrong, try and attempt it yourself first before asking it from someone. Getting used to ask someone is going to be troublesome in the long run. If you get stuck, then get help from your teachers (unless the teacher is unco-operative) in which case, seek help from your friends, or talk to your parents about it if you freely share stuff with them.

But anyway, hope that helps ^

Answer:

12

Step-by-step explanation:

12/4=3

3^2=9

3+9=12

Answer:

no,i don't think about it

Answer:

The Zscore for both test is the same

Step-by-step explanation:

Given that :

TEST 1:

score (x) = 75

Mean (m) = 65

Standard deviation (s) = 8

TEST 2:

score (x) = 75

Mean (m) = 70

Standard deviation (s) = 4

USING the relation to obtain the standardized score :

Zscore = (x - m) / s

TEST 1:

Zscore = (75 - 65) / 8

Zscore = 10/8

Zscore = 1.25

TEST 2:

Zscore = (75 - 70) / 4

Zscore = 5/4

Zscore = 1.25

The standardized score for both test is the same.

Answer:

8 3/5

false

Step-by-step explanation:

Answer:

5.25 miles

Step-by-step explanation:

Answer:

There is 5.25 miles in 9,240 yards

Step-by-step explanation:

1 mile is equal to 1760 yards, so the equation would be

9240/1760 = 5.25

Answer:

6

Step-by-step explanation:

Answer:

22 projects did not receive a perfect score

Step-by-step explanation:

12% or 25 is 3, meaning 3 got perfect scores. You would subtract 3 from 25 to get the amount of projects that didnt get a perfect score.

Answer:

52%

Step-by-step explanation:

25 x 4 =100

12 x 4 =48

100-48=52

Answer:

2

Step-by-step explanation:

a>0 is maximum value of f

Answer:

1. no solution

2. one solution

3. infinitely many solutions

Step-by-step explanation:

1. 4= -3

false

2. -5=6c+7

2=6c

c=3

3. 5a+7=5a+7

true

Answer:

No solution

One solution

Infinite number of solutions

Step-by-step explanation:

Answer:

angle 1 = 70 degree and angle 2=95 degree

Step-by-step explanation:

for the first angle

180 -70 = 110

and 180-110 = 70 ( opposite angles )

for the second angle

180-85 =95

and again 180-95 =85(opposite angles)

180-85=95 (the straight line property)