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3 years ago

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It took 7.2 minutes to upload 8 digital photographs from your computer to a website. At this rate, how long will it take to uplo

ad 20 photographs? How do I set this problem up?

1 answer:

kenny6666 [7]3 years ago

5 0

If it take some x minutes to upload some y digital photographs, it means it has an average of: x/y minutes to upload a single digital photograph. Then, to upload z photographs, you just multiply x/y by z.

Spoilers for answer:
If it take 7.2 minutes to upload 8 digital photographs, it means it has an average of: 7.2/8 = 0.9 minutes to upload a single digital photograph. This means that, by this rate, it will take 20 * 0.9 = 18 minutes to upload 20 photographs to the website.

You might be interested in

Alan is 5 years older than Bob. Bob is twice as old as Cindy. All their ages add up to 20. What are their ages?

Llana [10]

We can use a variable equation to solve this. Let A represent alan's age, B represent bob's age, and C represent Cindy's age. So Bob's age would be Alan's age - 5, or a -5 = B. Then Bob's age would be double Cindy's age, so that means 2 multiplied by Cindy's age = Bob's age, or 2C = B. Your two equations are:

A - 5 = B
2C = B

Also a third equation that helps is A + B + C = 20.

Finally, here are the ages.
Alan = 11 years old
Bob = 6 years old
Cindy = 3 years old.

PS: Sorry, I'm not that good at explaining things, but here are the answers

6 0

3 years ago

Consider the function f ( x ) = 5 x 3 − 3 x on the interval [ − 2 , 2 ] . Find the average or mean slope of the function on this

Slav-nsk [51]

Answer:

V

Step-by-step explanation:

7 0

2 years ago

Solve the following equations: (a) x^11=13 mod 35 (b) x^5=3 mod 64

tino4ka555 [31]

a.

$x^{11}=13\pmod{35}\implies\begin{cases}x^{11}\equiv13\equiv3\pmod5\\x^{11}\equiv13\equiv6\pmod7\end{cases}$

By Fermat's little theorem, we have

$x^{11}\equiv (x^5)^2x\equiv x^3\equiv3\pmod5$

$x^{11}\equiv x^7x^4\equiv x^5\equiv6\pmod 7$

5 and 7 are both prime, so $\varphi(5)=4$ and $\varphi(7)=6$ . By Euler's theorem, we get

$x^4\equiv1\pmod5\implies x\equiv3^{-1}\equiv2\pmod5$

$x^6\equiv1\pmod7\impleis x\equiv6^{-1}\equiv6\pmod7$

Now we can use the Chinese remainder theorem to solve for $x$ . Start with

$x=2\cdot7+5\cdot6$

Taken mod 5, the second term vanishes and $14\equiv4\pmod5$ . Multiply by the inverse of 4 mod 5 (4), then by 2.

$x=2\cdot7\cdot4\cdot2+5\cdot6$

Taken mod 7, the first term vanishes and $30\equiv2\pmod7$ . Multiply by the inverse of 2 mod 7 (4), then by 6.

$x=2\cdot7\cdot4\cdot2+5\cdot6\cdot4\cdot6$

$\implies x\equiv832\pmod{5\cdot7}\implies\boxed{x\equiv27\pmod{35}}$

b.

$x^5\equiv3\pmod{64}$

We have $\varphi(64)=32$ , so by Euler's theorem,

$x^{32}\equiv1\pmod{64}$

Now, raising both sides of the original congruence to the power of 6 gives

$x^{30}\equiv3^6\equiv729\equiv25\pmod{64}$

Then multiplying both sides by $x^2$ gives

$x^{32}\equiv25x^2\equiv1\pmod{64}$

so that $x^2$ is the inverse of 25 mod 64. To find this inverse, solve for $y$ in $25y\equiv1\pmod{64}$ . Using the Euclidean algorithm, we have

64 = 2*25 + 14

25 = 1*14 + 11

14 = 1*11 + 3

11 = 3*3 + 2

3 = 1*2 + 1

=> 1 = 9*64 - 23*25

so that $(-23)\cdot25\equiv1\pmod{64}\implies y=25^{-1}\equiv-23\equiv41\pmod{64}$ .

So we know

$25x^2\equiv1\pmod{64}\implies x^2\equiv41\pmod{64}$

Squaring both sides of this gives

$x^4\equiv1681\equiv17\pmod{64}$

and multiplying both sides by $x$ tells us

$x^5\equiv17x\equiv3\pmod{64}$

Use the Euclidean algorithm to solve for $x$ .

64 = 3*17 + 13

17 = 1*13 + 4

13 = 3*4 + 1

=> 1 = 4*64 - 15*17

so that $(-15)\cdot17\equiv1\pmod{64}\implies17^{-1}\equiv-15\equiv49\pmod{64}$ , and so $x\equiv147\pmod{64}\implies\boxed{x\equiv19\pmod{64}}$

5 0

2 years ago

If you have a 21oz cereal and the price is 2.94 what is the unit price

just olya [345]

For 21 Oz, price is 2.94
So, for 1 Oz, it would be: 2.94 / 21 = 0.14

In short, Your Answer would be $0.14 cereal per oz.

Hope this helps!

6 0

3 years ago

Read 2 more answers

Solve for x 0=3x^2+3x+7

Aloiza [94]

Answer:

x =(3-√-75)/-6=1/-2+5i/6√ 3 = -0.5000-1.4434i

x =(3+√-75)/-6=1/-2-5i/6√ 3 = -0.5000+1.4434i

Step-by-step explanation:

Rearrange:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :

0-(3*x^2+3*x+7)=0

Step by step solution:

Step 1:

Equation at the end of step 1 :

0 - (( $-3x^{2}$ + 3x) + 7) = 0

<u>Step 2:</u>

Pulling out like terms:

2.1 Pull out like factors:

$-3x^{2}$ - 3x - 7 = -1 • ( $3x^{2}$ + 3x + 7)

Trying to factor by splitting the middle term

2.2 Factoring $3x^{2}$ + 3x + 7

The first term is, $3x^{2}$ its coefficient is 3 .

The middle term is, +3x its coefficient is 3 .

The last term, "the constant", is +7

Step-1 : Multiply the coefficient of the first term by the constant 3 • 7 = 21

Step-2 : Find two factors of 21 whose sum equals the coefficient of the middle term, which is 3 .

-21 + -1 = -22

-7 + -3 = -10

-3 + -7 = -10

-1 + -21 = -22

1 + 21 = 22

3 + 7 = 10

7 + 3 = 10

21 + 1 = 22

Observation : No two such factors can be found !!

Conclusion : Trinomial can not be factored

Equation at the end of step 3 :

$-3x^{2}$ - 3x - 7 = 0

<u>Step 3:</u>

Parabola, Finding the Vertex:

3.1 Find the Vertex of y = $-3x^{2}$ -3x-7

For any parabola,Ax2+Bx+C,the x -coordinate of the vertex is given by -B/(2A) . In our case the x coordinate is -0.5000

Plugging into the parabola formula -0.5000 for x we can calculate the y -coordinate :

y = -3.0 * -0.50 * -0.50 - 3.0 * -0.50 - 7.0

or y = -6.250

Parabola, Graphing Vertex and X-Intercepts :

Root plot for : y = $-3x^{2}$ -3x-7

Axis of Symmetry (dashed) {x}={-0.50}

Vertex at {x,y} = {-0.50,-6.25}

Function has no real roots

Solve Quadratic Equation by Completing The Square

3.2 Solving $-3x^{2}$ -3x-7 = 0 by Completing The Square .

Multiply both sides of the equation by (-1) to obtain positive coefficient for the first term:

$3x^{2}$ +3x+7 = 0 Divide both sides of the equation by 3 to have 1 as the coefficient of the first term :

$x^{2}$ +x+(7/3) = 0

Subtract 7/3 from both side of the equation :

$x^{2}$ +x = -7/3

Now the clever bit: Take the coefficient of x , which is 1 , divide by two, giving 1/2 , and finally square it giving 1/4

Add 1/4 to both sides of the equation :

On the right hand side we have :

-7/3 + 1/4 The common denominator of the two fractions is 12 Adding (-28/12)+(3/12) gives -25/12

So adding to both sides we finally get :

$x^{2}$ +x+(1/4) = -25/12

Adding 1/4 has completed the left hand side into a perfect square :

$x^{2}$ +x+(1/4) =

(x+(1/2)) • (x+(1/2)) =

(x+(1/2))2

Things which are equal to the same thing are also equal to one another. Since

$x^{2}$ +x+(1/4) = -25/12 and

$x^{2}$ +x+(1/4) = (x+(1/2))2

then, according to the law of transitivity,

(x+(1/2))2 = -25/12

We'll refer to this Equation as Eq. #3.2.1

The Square Root Principle says that When two things are equal, their square roots are equal.

Note that the square root of

(x+(1/2))2 is

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

(x+(1/2))1 =

x+(1/2)

Now, applying the Square Root Principle to Eq. #4.2.1 we get:

x+(1/2) = √ -25/12

Subtract 1/2 from both sides to obtain:

x = -1/2 + √ -25/12

√ 3 , rounded to 4 decimal digits, is 1.7321

So now we are looking at:

x = ( 3 ± 5 • 1.732 i ) / -6

Two imaginary solutions :

x =(3+√-75)/-6=1/-2-5i/6√ 3 = -0.5000+1.4434i

or:

x =(3-√-75)/-6=1/-2+5i/6√ 3 = -0.5000-1.4434i

6 0

2 years ago