evaluate the function f(x)=4x^2-7x+7 find f(7)​

please I need the answer soon!

Answer:

1.944 ;

0.026

Step-by-step explanation:

Given :

Sample size, n = 34

Sample mean, xbar = 15

Population standard deviation, σ = 3

The hypothesis :

H0: μ ≤ 14

H1: μ > 14

The test statistic :

Test statistic = (xbar - μ) ÷ (σ/√(n))

Test statistic = (15 - 14) ÷ (3/√(34))

Test statistic = 1 / 0.5144957

Test statistic, Z = 1.944

The Pvalue :

Using the Pvalue from test statistic value :

Pvalue(1.944) = 0.026

Pvalue < α ; Reject H0

Answer:

The time required is 60.3 days.

Step-by-step explanation:

initial amount, No = 0.3 g

rate, r = 1.15 % per day = 0.0115 per day

final amount, N = 0.15 g

Let the time is t.

[tex]N = No e^{-rt}\\\\0.15 = 0.3 e^{-0.0115 t}\\\\0.5 =e^{-0.0115 t}\\\\- 0.6931 = - 0.0115 t \\\\t = 60.3 days[/tex]

Answer:

I believe it's A

Step-by-step explanation:

I'm not sure sorry if its wrong

Answer:

Step-by-step explanation:

slope of line through (6,-1) and (11,2) = (-1 - 2)/(6 - 11) = 3/5

slope of line through (5,-7) and (8,-2) = (-7 - (-2))/(8 - 5) = -5/3

product of the slopes = -1, so the lines are perpendicular.

Step-by-step explanation:

5% of 483759 is 24187.95

Answer: The answer is 24,187.95

Step-by-step explanation:

483759 Multiplied by 0.05 = 24,187.95

Notice that

[tex]\dfrac{4n+1}{8n+2}=\dfrac{4n+1}{2(4n+1)}=\dfrac12[/tex]

So by the root test,

[tex]\displaystyle\lim_{n\to\infty}\sqrt[n]{\left|\left(\frac12\right)^{2n}\right|} = \frac14 < 1[/tex]

and so the series converges (absolutely).

If one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.

What do we know?

We know that there are 15 billiard balls.

We also know that balls numbered 1 through 8 are solid-colored, so we have 8 solid-colored balls.

And the other 7 balls are striped.

Now we want to find the probability for a randomly selected ball to be a striped ball.

Because all the balls have the same probability of being randomly selected, the probability of randomly selecting a striped ball is equal to the quotient between the number of striped balls (7) and the total number of balls (15).

Then we have:

P = 7/15 = 0.467

That quotient is also what is called the "odds"

So if one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.

If you want to learn more, you can read:

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Answer:

[tex]{ \bf{ log_{a}(U) = x}} \\ { \boxed{ \tt{ {a}^{x} = U}}} \\ \\ { \bf{ log_{a}(V) = y}} \\ { \boxed{ \tt{ {a}^{y} = V }}}[/tex]

Answer:

x=9

Step-by-step explanation:

[tex]\sqrt{x}[/tex]=3

[tex]\sqrt{x}[/tex]^2=3^2

x=9

A line of symmetry would separate a shape to make multiple shapes that are exactly the same.

The answer is C.2

9514 1404 393

Answer:

  12

Step-by-step explanation:

Apparently, you want the sum a+b when ...

  [tex]\[\displaystyle\frac{\sqrt{600} + \sqrt{150} + 4\sqrt{54}}{6\sqrt{32} - 3\sqrt{50} - \sqrt{72}} = a\sqrt{b},\][/tex]

A calculator can show you the expression on the left evaluates to √243. In simplest terms, that is 9√3, so we have a=9, b=3 and ...

  a+b = 9+3 = 12

Answer:

12

Step-by-step explanation:

Answer:

30%

Step-by-step explanation:

you just add 10% and 20%

Hope it helps c:

Zelina scored 32% higher on the third quiz than on her first quiz.

The Percentage is defined as representing any number with respect to 100. It is denoted by the sign %.

Given that:-

From the given data we will see that:-

1 ) Zelina scored 10% higher on her second quiz than on her first quiz.

SQ = 1.10 FQ

2 ) On her third quiz, Zelina scored 20% higher than on her second quiz

TQ = 1.20SQ

From the above to expression solve for the first quiz:-

TQ = 1.20 x  1.10 FQ

TQ = 1.32FQ

Therefore Zelina scored 32% higher on the third quiz than on her first quiz.

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9514 1404 393

Answer:

  f(x) = -4(x +7)(x +1)

Step-by-step explanation:

The x-intercepts tell us that m=-7 and n=-1. We can use the given point to find 'a'.

  f(-4) = 36

  a(-4+7)(-4+1) = 36

  a = 36/-9 = -4 . . . . divide by the coefficient of 'a'

Filling in the known values, ...

  f(x) = -4(x +7)(x +1)

Answer:

marilyn isrestiring and wants to set up a 25-year annuity earns 7.

Answer:

1.047734151

Step-by-step explanation:

Type into calculator

1/2sin(2x)+cos(3x)

Answer:

it have to be letter c

Step-by-step explanation:

this the only problem matches with the question

The inequality represent the given phrase is 2x-11≤20+x. Therefore, option D is the correct answer.

Inequalities are the mathematical expressions in which both sides are not equal. In inequality, unlike in equations, we compare two values. The equal sign in between is replaced by less than (or less than or equal to), greater than (or greater than or equal to), or not equal to sign.

Given that, the difference of twice a number, x, and eleven is, at most, the sum of twenty and a number, x.

The difference of twice a number, x, and eleven is

2x-11

The sum of twenty and a number, x

20+x

So, inequality is 2x-11≤20+x

The inequality represent the given phrase is 2x-11≤20+x. Therefore, option D is the correct answer.

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Answer:

80 cm^2

Step-by-step explanation:

Let the width of the rectangle equal x. This means the length is x + 2, as it is 2 cm longer than the width. The formula for perimeter is: P = 2l + 2w, and substitute in the values of the length, width, and perimeter:

P = 2l + 2w

36 = 2(x + 2) + 2(x)

36 = 2x + 4 + 2x

36 = 4x + 4

4x = 32

x = 8

x represents the width, so the width is 8 and the length is 10. Area is length times width, so the area is 8 x 10 or 80 cm^2.

Step-by-step explanation:

let x be the width

p=2l+2w

36=2(2)+2(x)

36=4+2x

36-4=2x

32/2=2x/2(simplify)

x=16

therefore the width is 16cm

area of the rectangle is l×w

=2×16

=32cm"

therefore the area is 32cm"

Answer:

acute

Step-by-step explanation:

That triangle is an obtuse triangle

Answer:

Number of 7-digit numbers that can be made from the digit is 576

Step-by-step explanation:

Given the data in the question;

digits ⇒ 1, 2, 3, 4, 5, 6, 7

Number of odd numbers in the given digits = 4

Number of even numbers in the given digits = 3

now, we take the odd digits as a single unit.

so, number of ways the odd digits can be arranged with the unit will be 4!.

Now, lets consider the unit of 4 odd digits with 3 even digits.

there are 4 units.

so the number of possible arrangements of these 4 units = 4!

hence, Number of 7-digit numbers that can be made from the digits will be;

⇒ Number of possible arrangements of 4 units × Number of ways in which the odd digits can be arranged within the unit.

⇒ 4! × 4!

⇒ 576

Therefore, Number of 7-digit numbers that can be made from the digit is 576

Answer:

Mean = 35.56

Median = 35.5

Step-by-step explanation:

Given the data:

16 25 24 19 33 25 34 46 37

33 42 40 37 34 49 73 46 45

Reordered data :

16, 19, 24, 25, 25, 33, 33, 34, 34, 37, 37, 40, 42, 45, 46, 46, 49, 73

The mean = ΣX / n

n = sample size ; ΣX = sum of values

The mean = 658 / 18

The mean = 36.56

The Median = 1/2(n+1)th term

1/2(18+1)th term = 1/2(19)th term = 9.5 term

Median = (9th + 10th) / 2 = (34 + 37) / 2 = 35.5

Answer:

168).  C

169).  C

170).  C

Step-by-step explanation:

For the first angle, it is a right angle, so it measures 90 degrees.

x and 50 are complementary angles, meaning they add up to 90 degrees.

So, subtract 50 from 90 to get 40, which is equal to x.

45 and x are supplementary angles, meaning they add up to 180 degrees.

Subtract 45 from 180 to get 35 degrees, which is the measure of angle x.

All angles in a triangle add up to 180 degrees.

So, 70 + 56 = 126, 180 - 126 = 54.

Since the unknown angle is x - 5, 54 + 5 = 59, which the the measure of angle x - 5.

Answer:

D.

Step-by-step explanation:

Since the unit rate is in dollars per pound, we divide the cost (in dollars) by the weight (in pounds.)

($7.45)/(2.5 lb) = $2.98 per pound

Answer: D.

y' + 6y = f(t)

where

[tex]f(t)=\begin{cases}0&\text{if }0\le t\le2\\12&\text{if }2<t\le6\\0&\text{if }6<t<\infty\end{cases}[/tex]

You can write f(t) in terms of the unit step (i.e. Heaviside theta) function u(t), which is defined as

[tex]u(t)=\begin{cases}0&\text{if }t<0\\1&\text{if }t\ge0\end{cases}[/tex]

Then the DE is written as

y' + 6y = 12 u (t - 2) - 12 u (t - 6)

(a) Take the Laplace transform of both sides:

LT[y' + 6y] = LT[12 u (t - 2) - 12 u (t - 6)]

s Y - y (0) + 6Y = 12 (exp(-2s) - exp(-6s))/s

(b) Solve for Y :

(s + 6) Y = 12 (exp(-2s) - exp(-6s))/s + y (0)

Y = 12 (exp(-2s) - exp(-6s))/(s (s + 6)) + y (0)/(s + 6)

(c) Take the inverse transform:

LT⁻¹ [Y] = LT⁻¹[12 (exp(-2s) - exp(-6s))/(s (s + 6)) + y (0)/(s + 6)]

y = 12 LT⁻¹ [(exp(-2s) - exp(-6s))/(s (s + 6))] + y (0) LT⁻¹ [1/(s + 6)]

y = 12 u (t - 2) LT⁻¹ [1/(s (s + 6))] - 12 u (t - 6) LT⁻¹ [1/(s (s + 6))] + y (0) exp(-6t )

For the remaining inverse transform, break up into partial fractions:

1/(s (s + 6)) = a/s + b/(s + 6)

1 = a (s + 6) + bs

1 = (a + b) s + 6a

==>   6a = 1, a + b = 0   ==>   a = 1/6, b = -1/6

y = 2 u (t - 2) LT⁻¹ [1/s - 1/(s + 6)] - 2 u (t - 6) LT⁻¹ [1/s - 1/(s + 6)] + y (0) exp(-6t )

y = 2 u (t - 2) (1 - exp(-6t )) - 2 u (t - 6) (1 - exp(-6t )) + y (0) exp(-6t )

Answer:

157 cm²

Step-by-step explanation:

A cylinder is given to us and we need to find out the lateral surface area of the cylinder . We can see that the ,

Height = 5cm

Radius = 5cm

We know that we can find the lateral surface area of the cylinder as ,

[tex]\rm\implies LSA_{cylinder}= 2\pi r h [/tex]

Substitute upon the respective values ,

[tex]\rm\implies LSA = 2 \times 3.14 \times 5cm \times 5cm [/tex]

Multiply the numbers ,

[tex]\rm\implies \boxed{\blue{\rm LSA = 157 \ cm^2 }}[/tex]

Hence the Lateral surface area of the cylinder is 157 cm² .

[tex] \setlength{\unitlength}{1mm}\begin{picture}(5,5)\thicklines\multiput(-0.5,-1)(26,0){2}{\line(0,1){40}}\multiput(12.5,-1)(0,3.2){13}{\line(0,1){1.6}}\multiput(12.5,-1)(0,40){2}{\multiput(0,0)(2,0){7}{\line(1,0){1}}}\multiput(0,0)(0,40){2}{\qbezier(1,0)(12,3)(24,0)\qbezier(1,0)(-2,-1)(1,-2)\qbezier(24,0)(27,-1)(24,-2)\qbezier(1,-2)(12,-5)(24,-2)}\multiput(18,2)(0,32){2}{\sf{5cm}}\put(9,17.5){\sf{5cm}}\end{picture}[/tex]

Answer:

314.2 is the Surface area

Step-by-step explanation:

Hope it Helps! If you have any questions, feel free to comment! :)

2π(5)(5)+2π(5^2)

2π(25)+2[tex]\pi[/tex](25)

50π+50π=100π

314.2 is the answer. That's what we get after rounding up! :)

Answer:

Scores between 71 and 80 give a C grade.

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Scores on the test are normally distributed with a mean of 78.8 and a standard deviation of 9.8.

This means that [tex]\mu = 78.8, \sigma = 9.8[/tex]

Find the numerical limits for a C grade.

Above the bottom 20%(20th percentile) and below the top 45%(below the 100 - 45 = 55th percentile).

20th percentile:

X when Z has a p-value of 0.2, so X when Z = -0.84.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-0.84 = \frac{X - 78.8}{9.8}[/tex]

[tex]X - 78.8 = -0.84*9.8[/tex]

[tex]X = 70.57[/tex]

So it rounds to 71.

55th percentile:

X when Z has a p-value of 0.55, so X when Z = 0.125.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]0.125 = \frac{X - 78.8}{9.8}[/tex]

[tex]X - 78.8 = 0.125*9.8[/tex]

[tex]X = 80[/tex]

Scores between 71 and 80 give a C grade.

(B)

Step-by-step explanation:

Rewrite the equations into their standard forms. The first one can be rewritten as

[tex]10x - 12y = -5[/tex]

and the 2nd can be rewritten as

[tex]3x + 5y = -1[/tex]

Solving this system either by substitution or elimination, we get

[tex]x = -\dfrac{37}{86}\:\:\text{and}\:\:y= \dfrac{25}{86}[/tex]

If you add x + y, you'll get a negative number.

9514 1404 393

Answer:

  B. x + y < 0

Step-by-step explanation:

The two equations can be cleared of fractions by multiplying by 15.

  15(2/3(x +1) -4/5y) = 15(1/3)

  10(x +1) -12y = 5

  10x -12y = -5

and

  15(2/5x +1/3(2y +1)) = 15(1/5)

  6x +5(2y +1) = 3

  6x +10y = -2

  3x +5y = -1 . . . . . eliminate common factor of 2

__

You can find the solutions any way you like, but you can answer the question without doing that. The lines are not parallel, nor coincident, so there is exactly one solution. (choices C and D are incorrect)

If we can locate the solution relative to the line x + y = 0, we can tell if choice A or choice B is correct. A quick look at the intercepts of the equations tells us the solution cannot lie in quadrants 1 or 4. The negative y-intercept and shallow slope (-3/5) of the second equation tells us the solution must lie below the line x + y = 0. That means x+y < 0, choice B.

_____

In the attached graph, the line x+y=0 is dashed orange. Above that line, x+y>0; below that line, x+y<0. We see the intersection point of the red and blue lines is in the region where x+y < 0.

For standard form equation ax+by = c, the x- and y-intercepts are c/a and c/b, respectively, so are easy to find from that form. Knowing these makes it easy to make a sketch of the graph, locating the solution point relative to the line x+y = 0.

Answer: 3 shelves

Step-by-step explanation:

12 ÷ 3.1 = 3.87…

Since this is more than 3 but less than 4, we can build 3 full shelves with a leftover.

Answer:

24

Step-by-step explanation:

The number of rows (x) should b equal to the number of columns (x).

x²=576

x=√576 taking the square root of the product

x=24

Answer:

1) x+y=-2

x=-2-y

2) x-y=-8

substitude value of x

(-2-y)-y=-8

-2-2y=-8

-2y=-6

y=3

Substitute value of y in 1

x=-2-3

x=-5

Brainliest please~