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4 years ago

A train travels 25 miles in 20 minutes. What is the train speed in miles per hour?

1 answer:

7 0

So,

The rate of the train is 25mi/20mins. We need (x)mi/hr. We can do that by multiplying by 3.

25(3) = 75

The train's speed in mph is 75 mph.

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loris [4]

Answer:

30 i think

Step-by-step explanation:

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4 years ago

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Multiply: 6√x * 4√y^3

EastWind [94]

Answer:

The third answer option is correct. sqrt(x) = x^(1/2). So sqrt(121) = 121^(1/2)

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3 years ago

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There are 2112 people in a concert.

nadya68 [22]

Answer:

75% of 352 children are boys

Step-by-step explanation:

If 5/6 of the people participaticipants to a concert are adults then 1 out of 6 prople are children so we may reach a number of 2112:6=352 children

if 25% of the children are girls then 75% are boys

88×3=264 boys

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4 years ago

Use properties of addition to evaluate the expression. −35+7+(−15) Enter your answer in the box.

frutty [35]

Your answer will be -43

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3 years ago

The average value of a function f over the interval [−1,2] is −4, and the average value of f over the interval [2,7] is 8. What

Anna71 [15]

The average value of a continuous function f(x) over an interval [a, b] is

$\displaystyle f_{\mathrm{ave}[a,b]} = \frac1{b-a}\int_a^b f(x)\,dx$

We're given that

$\displaystyle f_{\rm ave[-1,2]} = \frac13 \int_{-1}^2 f(x) \, dx = -4$

$\displaystyle f_{\rm ave[2,7]} = \frac15 \int_2^7 f(x) \, dx = 8$

and we want to determine

$\displaystyle f_{\rm ave[-1,7]} = \frac18 \int_{-1}^7 f(x) \, dx$

By the additive property of definite integration, we have

$\displaystyle \int_{-1}^7 f(x) \, dx = \int_{-1}^2 f(x)\,dx + \int_2^7 f(x)\,dx$

so it follows that

$\displaystyle f_{\rm ave[-1,7]} = \frac18 \left(\int_{-1}^2 f(x)\,dx + \int_2^7 f(x)\,dx\right)$

$\displaystyle f_{\rm ave[-1,7]} = \frac18 \left(3\times(-4) + 5\times8\right)$

$\displaystyle f_{\rm ave[-1,7]} = \boxed{\frac72}$

7 0

3 years ago