7th grade math help me plzzz

Answer:

f(f(-4) = -2

Step-by-step explanation:

f(f(-4))

First find the value of f(-4)

f(-4) = 2

Now find f(2)

f(2) = -2

Answer:

-3x= 2×2-4

Step-by-step explanation:

-3x= 4-4

-3x= 0

divide both sides by the co-efficient of x

-3x/-3= 0÷-3

x = 0

The solution of the quadratic equation 2x² + 3x − 4 = 0 will be 2.35 and negative 0.85.

Let the equation be ax² + bx + c = 0. Then the roots of the equation will be given as,

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

The equation is given below.

−3x = 2x² − 4

Simplify the equation, then we have

2x² − 4 = −3x

2x² + 3x − 4 = 0

Then the roots of the equation are given as,

x = [3 ± √(3² - 4 · 2 · (-4))] / (2 · 2)

x = (3 ± 6.403) / 4

x = 2.35, -0.85

The solution of the quadratic equation 2x² + 3x − 4 = 0 will be 2.35 and negative 0.85.

More about the roots of the equation link is given below.

https://brainly.com/question/12029673

#SPJ2

Answer:

[tex]Mean = 4.35[/tex]

[tex]SD = 0.5655[/tex]

Step-by-step explanation:

Given

[tex]n = 5[/tex]

[tex]p = 0.87[/tex]

Solving (a): Mean

[tex]Mean = np[/tex]

[tex]Mean = 5 * 0.87[/tex]

[tex]Mean = 4.35[/tex]

Solving (b): Standard Deviation (SD)

[tex]SD = np(1 - p)[/tex]

[tex]SD = 5 * 0.87(1 - 0.87)[/tex]

[tex]SD = 5 * 0.87 * 0.13[/tex]

[tex]SD = 0.5655[/tex]

Answer:

Week 1 - 20

Week 2 - 27

Week 3- 34

Week 4 - 41

Week 5 - 48

Etc, etc,...

Step-by-step explanation:

The values increase by 7 each week.

Answer:

i hope this helps but the slopes are y = 4/3x + 12 and y = 6/5

I = PRT

Divide both sides by PR

I/(PR) = T

Answer:

1.)Angle Addition Postulate

2.)Alternate interior Angle Theorem

3.)m/_1+m/_2+m/_

Step-by-step explanation:

I took the test

Answer:

11. 92- corresponding angles theorem

12. 92- vertical angles theorem

13. 88- ???

14. 106- same side interior angles theorem

15. 106- supplementary angles theorem (not sure about the reasoning)

16. 106- supplementary angles theorem (not sure about the reasoning)

Answer:

The value of the car after one year is $1000

Step-by-step explanation:

$5000 * 0.2 = 1000.

You can say the 20% = 0.2.

So it is depreciated by 0.2.

You multiply the number (5000) by 0.2

5000 * 0.2 = 1000.

Answer:

The answer is 1,000

Step-by-step explanation:

because 20% of 5000 is the answer which is 1,000

Answer:

a function

Step-by-step explanation:

Answer:

No

Step-by-step explanation:

The function has more than one point on one line of Y.

Answer:

heres the actual answer.

Step-by-step explanation:

Answer:

perimeter =2(l+w)

6.6=2(l + 1.8)

6.6= 2L + 3.6

L=3/2 =1.5

ans =1.5

Answer:

x is 28

Step-by-step explanation:

When two lines intersected in a point, then they formed two pairs of vertically opposite angles. The vertically opposite angles are equal in measures

Let us solve our question

∵ AB and CD are straight lines intersected at O

∴ ∠AOC and ∠DOB are vertically opposite angles

∴ ∠AOD and ∠COB are vertically opposite angles

→ The vertically opposite angles are equal in measures

∴ m∠AOC = m∠DOB

∴ m∠COB = m∠AOD

→ ∠ COB is formed from ∠COE, ∠EOF, and ∠FOB

∵ m∠COB = m∠COE + m∠EOF + m∠FOB

∵ m∠COE = 3x, m∠EOF = x, m∠FOB = x + 12

∴ m∠COB = 3x + x + x + 12

→ Add the like terms

∴ m∠COB = 5x + 12

∵ m∠AOD = 152°

∵  m∠COB = m∠AOD

∴ 5x + 12 = 152

→ Subtract 12 from both sides

∴ 5x + 12 - 12 = 152 - 12

∴ 5x = 140

→ Divide both sides by 5

∴ [tex]\frac{5x}{5}=\frac{140}{5}[/tex]

∴ x = 28

→ To justify the solution substitute x by 28 in m∠COB the answer must

   be 152°

∵ m∠COB = 5x + 12

∵ x = 28

∴ m∠COB = 5(28) + 12

∴ m∠COB = 140 + 12

∴ m∠COB = 152°

∴ The value of x is correct

Answer:

37485947

Step-by-step explanation:

Answer:

I think that the answer is 28827

.............................

Answer:

x=2 - 4y/5

y = 5/2 − 5x/4

Step-by-step explanation:

I don't know what you are asking for specifically, but here is both!!

Answer:

-10

Step-by-step explanation:

n - 8 = -18

n = -10

Negative 10

Or -10

Eight more than -18 is -10

Answer:

74893 students per year

Step-by-step explanation:

The Average rate of change is calculated as

= Difference in number of students / Difference in years

= 3120 thousand - 5217 thousands/ 2008 - 1980

= (3120000 - 5217000)/(2008 - 1980)

= -2097000/28

= -74892.857143 per year

Therefore, the average rate of change

per year in the number of high school dropouts is approximately 74893 students per year

Answer:

I think is sometimes

Step-by-step explanation:

Answer:

The answer is always

Answer:

324.848

288.464

316.112

337.856

Step-by-step explanation:

Given that :

Mean (m) = 350

Standard deviation (σ) = 48

Determine the value of x for the following :

Using the z probability calculator :

a.) 70% of the values are greater than x.

1 - 0.7 = 0.3

P(x < 30%) = P(x < 0.3) = - 0.524 = z

Z = (x - m) / σ

x = (z * σ) + m

X = (- 0.524 * 48) + 350 = 324.848

b.) x is less than 10% of the values.

P(x < 0.1) = - 1.282 = z

X = (- 1.282 * 48) + 350 = 288.464

C.) 24% of the values are less than x

P(x < 0.24) = - 0.706 = z

X = (- 0.706 * 48) + 350 = 316.112

D.) x is greater than 60% of the values

P(x > 0.6) = -0.253 = z

X = (- 0.253 * 48) + 350 = 337.856

Answer:

A. -5 - 3x >10

Step-by-step explanation:

-5 - 3(-6) >10

-5 + 18 >10

13 >10

Answer:

13 1/3

Step-by-step explanation:

im sure this is right btw

Answer:

[tex]Area = 6 * 10^3\ m^2[/tex]

Step-by-step explanation:

Given

[tex]Area = 6000m^2[/tex]

Required

Write as a number by power of 10

[tex]Area = 6000m^2[/tex]

Split 6000 as 6 * 1000

[tex]Area = 6 * 1000m^2[/tex]

Express 1000 as 10^3 --- Law of indices

[tex]Area = 6 * 10^3\ m^2[/tex]

Answer:

Present age of A = 16 years

Present age of B = 12 years

Step-by-step explanation:

Let the age of B be x years.

Therefore, age of A = (x + 4) years

Four years ago:

Age of A = (x + 4 - 4) = x years

Age of B = (x - 4) years

According to the given information:

[tex] \frac{x}{x - 4} = \frac{3}{2} \\ \\ 2x = 3(x - 4) \\ \\ 2x = 3x - 12 \\ \\ 2x - 3x = - 12 \\ \\ - x = - 12 \\ \\ x = 12 \\ \\ x + 4 = 12 + 4 = 16 \\ \\ present \: age \: of \: a = 16 \: yeras \\ \\ present \: age \: of \: b = 12 \: years \\ [/tex]

Answer:

15.4

Step-by-step explanation:

35 x 0.44 = 15.4

Answer:

The proportion of individuals score at most 74 points on this test is 70%.

Step-by-step explanation:

The complete question is:

Suppose that the scores on a reading ability test are normally distributed with a mean of 70 and a standard deviation of 8. What proportion of individuals score at most 74 points on this test? Round your answer to at least four decimal places.

Solution:

Let X represent the scores on a reading ability test.

It is provided that [tex]X\sim N(70,8^{2})[/tex].

Compute the probability that an individuals score is at most 74 points on this test as follows:

[tex]P(X\leq 74)=P(\frac{X-\mu}{\sigma}\leq \frac{74-70}{8})[/tex]

                 [tex]=P(Z<0.50)\\=0.69146\\\approx 0.70[/tex]

Thus, the proportion of individuals score at most 74 points on this test is 70%.

Answer:

60 degrees

Step-by-step explanation:

60 degrees because all sides are equal and 180/3 is 60.

Answer:

176.37 orrrr 176

Step-by-step explanation:

Answer:

176 pounds

Step-by-step explanation:

Answer:

A

it is asking for its absolute value

Step-by-step explanation:

Answer:

Step-by-step explanation:

The given information shows that X and Y are two variables with  joint probability distribution as follows:

X/Y         1        2        3         Total

1            0.1    0.05     0.1       0.25  

2           0.1     0.3      0.05    0.45

3           0.05  0.1       0.15     0.3

Total    0.25   0.45    0.3      1.00

Thus, the required probability is:

[tex]P(Y = 1|X=3) = \dfrac{P(Y=1,X=3)}{P(X=3)}[/tex]

[tex]P(Y = 1|X=3) = \dfrac{0.05}{0.1}[/tex]

[tex]P(Y = 1|X=3) =0.5[/tex]

The calculated probability value of Y =1, given that X = 3 is 0.5

[tex]P(Y = 2|X=3) = \dfrac{P(Y=2,X=3)}{P(X=3)}[/tex]

[tex]P(Y = 2|X=3) = \dfrac{0.1}{0.1}[/tex]

[tex]P(Y = 2|X=3) = 1.00[/tex]

The calculated probability value of Y =2, given that X = 3 is 1.00

[tex]P(Y = 3|X=3) = \dfrac{P(Y=3,X=3)}{P(X=3)}[/tex]

[tex]P(Y = 3|X=3) = \dfrac{0.15}{0.1}[/tex]

[tex]P(Y = 3|X=3) =1.5[/tex]

The calculated probability value of Y =3, given that X = 3 is 1.50

B.

From the joint probability distribution table, we can see that the probability value of the intersection X = 3 and Y = 3 is 1.50

i.e

P(X =3, Y =3) = 1.5

However;

the marginal probability of X = 0.3

the marginal probability of Y = 0.3

P(X =3)(Y=3) = 0.3 × 0.3 = 0.09

∴

≠ P(X =3)(Y=3)

Thus;

NO, the random variables X and Y are not independent.

C.

P(X+Y > 2) = P(X =2, Y = 1) + P( Y =2, X=1) + P(Y = 3, X= 1) + P( Y =2, X=2) +

                    P(Y =3, X=2) + P(Y =1, X =3) + P( Y =2, X =2) +P(Y =3, X =3)

P(X+Y > 2) =  0.1 + 0.05 + 0.1 + 0.3 + 0.05 + 0.05 + 0.1 + 0.15

P(X+Y > 2) = 0.9

P(XY =3)   =    P(X =2, Y =1 ) + P( Y =1 , X = 2)

P(XY =3)   = 0.10 + 0.05

P(XY =3)   = 0.15

P(XY > 1) = 0.1 + 0.05 + 0.1 + 0.1 + 0.3 + 0.05 + 0.05 + 0.1 + 0.15

P(XY > 1) = 1.00