There are 84 students in a speech contest. Yesterday, 1/4 of them gave their speeches. Today, 3/7 of the remaining students gave their speeches. How many students still haven't given their speeches?

Answer:

Step-by-step explanation:

This is a super simple problem. I'm going to walk through it as I do when I teach this to my students for the first time.

We are given a rectangle. We are told to find how fast the area is changing under certain conditions. That tells us that the main equation for this problem is the area formula for a rectangle which is

[tex]A=lw[/tex]. If we are looking for the rate at which the rectangle's area is changing, that means that we need to find the derivative of the area implicitly. This derivative is found using the product rule because the length is being multiplied by the width:

[tex]\frac{dA}{dt}=l\frac{dw}{dt}+w\frac{dl}{dt}[/tex] . If our unknown is the rate at which the area is changing, [tex]\frac{dA}{dt}[/tex], that means that everything else has to have a value (because you can only have one unknown in an equation). Here's what we're told:

The length of the rectangle is increasing at a rate of 7 cm/s, so that satisfies our [tex]\frac{dl}{dt}[/tex];

the width is increasing at a rate of 6 cm/s, so that satisfies our [tex]\frac{dw}{dt}[/tex];

and all of this is going on when the length = 12 and the width = 8. It looks like everything will have a value except for our unknown. Filling in:

[tex]\frac{dA}{dt}=12(6)+8(7)[/tex] and

[tex]\frac{dA}{dt}=72+56[/tex] so

[tex]\frac{dA}{dt}=128\frac{cm^2}{s}[/tex]

Answer:

The domain and range remain the same.

Step-by-step explanation:

Hi there!

First, we must determine what increasing a by 2 really does to the exponential function.

In f(x)=ab^x, a represents the initial value (y-intercept) of the function while b represents the common ratio for each consecutive value of f(x).

Increasing a by 2 means moving the y-intercept of the function up by 2. If the original function contained the point (0,x), the new function would contain the point (0,x+2).

The domain remains the same; it is still the set of all real x-values. This is true for any exponential function, regardless of any transformations.

The range remains the same as well; for the original function, it would have been [tex]y\neq 0[/tex]. Because increasing a by 2 does not move the entire function up or down, the range remains the same.

I hope this helps!

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:

Step-by-step explanation:

In the US, a decimal point is represented by a period. This value is interpreted as an integer with no fractional part, so the fractional part is zero:

 12,963.00

__

Some other places, a comma is used to identify the beginning of the decimal fraction. In that form, this number has a fractional part that has 3 as its thousandths digit. The value of 3 is less than 5, so the number is simply truncated at the hundredths place.

  12,96

If the thousandths digit were 5 or greater, then 1 hundredth would be added to the truncated number.

Step-by-step explanation:

Here,

by formula a^2+b^2=(a+b)^2-2ab

so,

or,(a+b)^2-2ab

or,(73)^2-2×65

or,5329-126

=5203 is the answer

Answer:

the second one

Step-by-step explanation:

it is not going in any general direction

Answer:

B

Step-by-step explanation:

Answer:

3x³+3x²+3x+8+[tex]\frac{4}{x-1}[/tex]

Step-by-step explanation:

You can use synthetic division for this problem since the divisor is in (x-a) form. The fraction is the remainder over the divisor.

9514 1404 393

Answer:

  C.  2cos²(x)

Step-by-step explanation:

The relevant identities are ...

  cos(2x) = cos²(x) -sin²(x)

  cos²(x) = 1 -sin²(x)

__

Then the expression can be simplified to ...

  cos(2x) +1 = (cos²(x) -sin²(x)) +1 = cos²(x) +(1 -sin²(x)) = cos²(x) +cos²(x)

  = 2cos²(x)

Answer:

I am pretty sure it is B.

Step-by-step explanation:

This is a line with a positive slope, therefore we can discard c and d.

the sign < will mean that the shaded in area will be on your right side.

Answer:

9/10

Step-by-step explanation:

The first two digit number is 10 and the last is 99. That's a total of 99-10+1 numbers in all. That simplifies to 90. (Just like if we wanted to see how many numbers was 3,4,5, we would do 5-3+1=3 to get the total number.

Anyways, let's consider first how many 2 digjt numbers whose digits are equal. You have 11 22,33,44 55,66,77,88,99 which is 9 numbers total.

So the amount of 2 digits number whose digits differ is 90-9=81.

The probability that a 2 digit number have different digits is 81/90.

This can reduce. Divide top and bottom by 9 giving 9/10.

Answer:

A. Increase speed to approximately 7.1 mph so that you cover the field more.

Step-by-step explanation:

The soil samples for the next field require more fertilizer coverage therefore there is need for more field coverage by the equipment. The speed of the tractor will be increase to 7.1 mph so that greater area can be covered in lesser time.

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:

X=1

f(x)=16^1

=16

X=2

f(x)=16^2

256

X=3

f(x)=16^3

=4096

X=4

f(x)=16^4

=65536

Here are four different ways to rewrite the function f(x) = 16^x, using a different base for each case:

Using base 2:

f(x) = (2^4)^x = 2^(4x)

Using base 3:

f(x) = (3^2)^x = 3^(2x)

Using base 10:

f(x) = (10^(log10(16)))^x = 10^(log10(16) * x)

Using base e (natural logarithm):

f(x) = (e^(ln(16)))^x = e^(ln(16) * x)

In these rewritten forms, the exponentiation of the base is expressed as a simpler expression.

This involves the new base, which helps to illustrate the relationship between the original function and the different bases used.

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Answer:

3.418

Step-by-step explanation:

3.4175

3.4178

u round if the number behind it is higher than 5

Answer:

Step-by-step explanation:

11/20 = 55/100 = 55%

Answer:

ON = KJ

Step-by-step explanation:

JKL = NOP

We know the angles match

<J = <N

<K = <O

< L = <P

And we know

JK = NO

KL =  OP

JL = NP

We are looking for ON = KJ

9514 1404 393

Answer:

  (d)  KJ

Step-by-step explanation:

The segment of interest is named using the 2nd and 1st letters of the right side of the similarity statement.

The corresponding segment will be named using the 2nd and 1st letters of the left side of the similarity statement: KJ.

If x + 1, x - 5, and x - 2 are in a geometric progression, then there is some constant r for which

x - 5 = r (x + 1)

==>   r = (x - 5) / (x + 1)

and

x - 2 = r (x - 5)

==>   r = (x - 2) / (x - 5)

Then

(x - 5) / (x + 1) = (x - 2) / (x - 5)

Solve for x :

(x - 5)² = (x - 2) (x + 1)

x ² - 10x + 25 = x ² - x - 2

-9x = -27

x = 3

It follows that the ratio between terms is

r = (3 - 5) / (3 + 1) = -2/4 = -1/2

Now, assuming x + 1 = 4 is the first term of the G.P., the n-th term a(n) is given by

a(n) = 4 (-1/2)ⁿ⁻¹

The sum of the first 12 terms - denoted here by S - is then

S = 4 (-1/2)⁰ + 4 (-1/2)¹ + 4 (-1/2)² + … + 4 (-1/2)¹¹

Solve for S :

S = 4 [(-1/2)⁰ + (-1/2)¹ + (-1/2)² + … + (-1/2)¹¹]

(-1/2) S = 4 [(-1/2)¹ + (-1/2)² + (-1/2)³ + … + (-1/2)¹²]

==>   S - (-1/2) S = 4 [(-1/2)⁰ - (-1/2)¹²]

==>   3/2 S = 4 (1 - 1/4096)

==>   S = 8/3 (1 - 1/4096)

==>   S = 1365/512

9514 1404 393

Answer:

Step-by-step explanation:

We observe that the second equation of System B has had the x-term eliminated. That can be accomplished by adding 3 times the first equation to the second.

"To get System B, the second equation in System A was replaced by the sum of that equation and 3 times the first equation. The solution is the same as the solution to System A."

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:

A

Step-by-step explanation:

We need to find a equation that is where the domain is all real numbers and the range is all real numbers greater than -3

A is right, the domain of a absolute value function is all real numbers. The range of a absolute value is all numbers greater than or equal to zero but if we subtract 3, it changes into all real numbers greater than or equal to -3

Answer:

[tex] x \div 1[/tex]

[tex] = x[/tex]

Answer:

[tex]x\div 1=x[/tex]

Step-by-step explanation:

When x is divided by one it is called reciprocal.

reciprocal is the inverse of a number or a value.

examples: The reciprocal of 3 is 1/3, and the reciprocal of 5 is 1/3.

OAmalOHopeO

Answer:

No

Step-by-step explanation:

Let's look at an example

24

24 is divisible by 6   24/6 = 4  

24 is divisible by 8   24/8 = 3

24 is not divisible by 48  24/48 = 1/2  which is not an integer

Answer: x= 2.5, y = 10

Step-by-step explanation:

I'm going to assume that these photocopies are proportional in relations to each other.

If they're proportional, you can set up two proportions:

[tex]1) \frac{x}{5} =\frac{3}{6} \\\\2) \frac{5}{y} =\frac{3}{6}[/tex]

And cross-multiply:

[tex]1) 6x = 5*3 \\\\2) 3y = 5*6[/tex]

Then solved for x and y:

[tex]1) 6x = 15\\x=\frac{15}{6} =\frac{5}{2} =2.5 \\\\2) 3y = 30\\y=\frac{30}{3} =10[/tex]

Answer:

0.19

Step-by-step explanation:

Jane bought a shoe for 54.82 euros

She gave the store owner 55 euros

= 55-54.82

= 0.18 euros to franc

= 0.18× 1.08222

= 0.19 franc

Answer:

$6.75

Step-by-step explanation:

The regular price is $15 dollars. The discount is 55% off the $15.

15 * 0.55 = 8.25

15 - 8.25 = 6.75

Hope this helps.

Answer:

discount =8.25

New price 6.75

Step-by-step explanation:

15 is the regular price

The discount is 55%

15*.55

8.25

The new price is the regular price minus the discount

15-8.25

6.75

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~

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.

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Answer:

x = -2

Step-by-step explanation:

x^2 + 4x + 4 = 0

quadratic formula:

-b +or- sqrt(b^2-4ac)/2a

-4 +/- sqrt ((-4)^2-4*1*4)/2*1

-4+/- sqrt(16-16) / 2

-4 +/- 0 / 2

-4/2

-2