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3 years ago

9

at the library, you find 9 books on a certain topic. the librarian tells you that 55% of the books on this topic have been signe

d out. how many books does the library have a available on the topic?

1 answer:

e-lub [12.9K]3 years ago

8 0

Multiply 9 books by 55% by doing

9 x .55 = 4.95

We can't have 4.95 books, though so it rounds down to 4 because you can't just add another .05.

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Please help Factor completely. Show your work (as much work as possible, including a list of factors if

Elena-2011 [213]

Answer:

Step-by-step explanation:

4) x² - 14x + 48

We would find two numbers such that their sum or difference is -14x and their product is 48x².

The two numbers are - 6x and - 8x. Therefore,

x² - 6x - 8x + 48

x(x - 6) - 8(x - 6)

(x - 8)(x - 6)

5) 2x² + 21x - 11

We would find two numbers such that their sum or difference is 21x and their product is - 22x².

The two numbers are 22x and - x. Therefore,

2x² + 22x - x - 11

2x(x + 11) - 1(x + 11)

(2x - 1)(x + 11)

6) 5a² - 125

5 is a common factor. So we would factorize 5. It becomes

5(a² - 25)

Simplifying further, it becomes

5(a + 5)(a - 5)

5 0

3 years ago

Consider a particle moving along the x-axis where x(t) is the position of the particle at time t, x' (t) is its velocity, and x'

vodka [1.7K]

Answer:

a) $v(t) =x'(t) = \frac{dx}{dt} = 3t^2 -12t +9$

$a(t) = x''(t) = v'(t) =6t-12$

b) $0$

c) $a(t) = x''(t) = v'(t) =6t-12$

When the acceleration is 0 we have:

$6t-12=0, t =2$

And if we replace t=2 in the velocity function we got:

$v(t) = 3(2)^2 -12(2) +9=-3$

Step-by-step explanation:

For this case we have defined the following function for the position of the particle:

$x(t) = t^3 -6t^2 +9t -5 , 0\leq t\leq 10$

Part a

From definition we know that the velocity is the first derivate of the position respect to time and the accelerations is the second derivate of the position respect the time so we have this:

$v(t) =x'(t) = \frac{dx}{dt} = 3t^2 -12t +9$

$a(t) = x''(t) = v'(t) =6t-12$

Part b

For this case we need to analyze the velocity function and where is increasing. The velocity function is given by:

$v(t) = 3t^2 -12t +9$

We can factorize this function as $v(t)= 3 (t^2- 4t +3)=3(t-3)(t-1)$

So from this we can see that we have two values where the function is equal to 0, t=3 and t=1, since our original interval is $0\leq t\leq 10$ we need to analyze the following intervals:

$0< t$

For this case if we select two values let's say 0.25 and 0.5 we see that

$v(0.25) =6.1875, v(0.5)=3.75$

And we see that for $a=0.5 >0.25=b$ we have that f(b)>f(a) so then the function is decreasing on this case.

$1$

We have a minimum at t=2 since at this value w ehave the vertex of the parabola :

$v_x =-\frac{b}{2a}= -\frac{-12}{2*3}= -2$

And at t=-2 v(2) = -3 that represent the minimum for this function, we see that if we select two values let's say 1.5 and 1.75

v(1.75) =-2.8125< -2.25= v(1.5) so then the function sis decreasing on the interval 1<t<2

$2$

We see that the function would be increasing.

$3$

For this interval we will see that for any two points a,b with $a>b$ we have $f(a)>f(b)$ for example let's say a=3 and b =4

$f(a=3) =0 , f(b=4) =9 , f(b)>f(a)$

The particle is moving to the right then the velocity is positive so then the answer for this case is: $0$

Part c

$a(t) = x''(t) = v'(t) =6t-12$

When the acceleration is 0 we have:

$6t-12=0, t =2$

And if we replace t=2 in the velocity function we got:

$v(t) = 3(2)^2 -12(2) +9=-3$

5 0

3 years ago

On Friday a local hamburger shop sold a combined total of 564 hamburgers and cheeseburgers. The number of cheeseburgers sold was

Illusion [34]

Answer:

I believe it's 188

Step-by-step explanation:

If there was a total of 564 and the cheeseburgers was three times the amount, you need to divide 564 by 3. 564 divided by 3 equals to 188. I am pretty sure this could be the correct answer!

3 0

2 years ago

Read 2 more answers

What units could you use to measure the height of a hexagonal prism?

konstantin123 [22]

No aswer for that question

4 0

3 years ago

Make a table of values for the function rule. then graph the function. y=-x²+4

lakkis [162]

Answer:

check the attached picture

Step-by-step explanation:

Given function is $y=-x^2+4$ .

Now we need to make a table of values for the function rule then graph the function.

We are free to plug any values of x like -3,-2,-1,0,1,2,3,... etc becaues domain of polynomial function is all real numbers.

Let's plug x=1 into given function to find the y-value

$y=-x^2+4$

$y=-(1)^2+4$

$y=-1+4$

$y=3$

Hence the first point is (1,3).

Same way we can find few more points to complete the table then graph those points and connect them to get the final graph.

x y

-2 8

-1 5

0 4

1 5

2 8

5 0

3 years ago