Can someone help me with this so I don't get in trouble??

The graph below shows Roy's distance from his office (y), in miles, after a certain amount of time (x), in minutes: Graph titled

Marina CMI [18]

Answer:

Felix

Step-by-step explanation:

The graph contains 3 segments,

first one is for the first 4minutes,

second one is for the next 2 minutes (standing still)

third one is for the last 2 minutes.

Only Felix has it right, the other students use absolute time in their statements, in stead of the difference between start and end. (e.g., from 4 to 6 is 2 minutes).

8 0

3 years ago

What is the simplified form of x minus 2 over x squared plus x minus 6divided byx squared plus 5x plus 4 over x plus 4?

tatyana61 [14]

Answer:

$\dfrac{1}{x^2+4x+3}$

Step-by-step explanation:

You have asked for the simpilfied form of ...

$x-\dfrac{2}{x^2}+x-\dfrac{6}{x^2}+5x+\dfrac{4}{x}+4$

That would be ...

$\dfrac{7x^3+4x^2+4x-4}{x^2}$

We suspect that's not what you meant. Parentheses are required for grouping when you write math expressions in text form. They work best using math symbols instead of words. We think you mean

... ((x -2)/(x^2 +x -6))/((x^2 +5x +4)/(x +4))

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Maybe you want to simplify ...

$\displaystyle\frac{\left(\frac{x-2}{x^2+x-6}\right)}{\left(\frac{x^2+5x+4}{x+4}\right)}=\frac{(x-2)(x+4)}{(x-2)(x+3)(x+4)(x+1)}\\\\=\frac{1}{(x+1)(x+3)}=\frac{1}{x^2+4x+3}$

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<em>Comment on simplifying rational expressions</em>

Division of fractions works the same whether you're working with numbers or polynomials (or anything else). Dividing by something is the same as multiplying by its inverse (reciprocal).

(a/b)/(c/d) = (a/b)·(d/c)

I learned this as "invert and multiply". I've recently seen it referred to as "copy dot flip", meaning you copy the numerator, use a dot symbol to indicate multipication, then flip the denominator (make its reciprocal) to become what you're multiplying by.

8 0

3 years ago

When a sunfloweris 2 weeks old it is 38 centimeters tall when it is 6 weeks old it is 114 cm tall how tall is it when it is 3 ½

Anna11 [10]

2 wk --- 38 cm
3.5 wk --- x cm
x = 3.5 wk x 38 cm
---------------------
2 wk
x= 66.5 cm

5 0

3 years ago

Suppose after 2500 years an initial amount of 1000 grams of a radioactive substance has decayed to 75 grams. What is the half-li

krok68 [10]

Answer:

The correct answer is:

Between 600 and 700 years (B)

Step-by-step explanation:

At a constant decay rate, the half-life of a radioactive substance is the time taken for the substance to decay to half of its original mass. The formula for radioactive exponential decay is given by:

$A(t) = A_0 e^{(kt)}\\where:\\A(t) = Amount\ left\ at\ time\ (t) = 75\ grams\\A_0 = initial\ amount = 1000\ grams\\k = decay\ constant\\t = time\ of\ decay = 2500\ years$

First, let us calculate the decay constant (k)

$75 = 1000 e^{(k2500)}\\dividing\ both\ sides\ by\ 1000\\0.075 = e^{(2500k)}\\taking\ natural\ logarithm\ of\ both\ sides\\In 0.075 = In (e^{2500k})\\In 0.075 = 2500k\\k = \frac{In0.075}{2500}\\ k = \frac{-2.5903}{2500} \\k = - 0.001036$

Next, let us calculate the half-life as follows:

$\frac{1}{2} A_0 = A_0 e^{(-0.001036t)}\\Dividing\ both\ sides\ by\ A_0\\ \frac{1}{2} = e^{-0.001036t}\\taking\ natural\ logarithm\ of\ both\ sides\\In(0.5) = In (e^{-0.001036t})\\-0.6931 = -0.001036t\\t = \frac{-0.6931}{-0.001036} \\t = 669.02 years\\\therefore t\frac{1}{2} \approx 669\ years$

Therefore the half-life is between 600 and 700 years

5 0

3 years ago

What’s the correct answer????

adell [148]

Answer:

$39

Step-by-step explanation:

(hope you get a 100%:))

7 0

3 years ago