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3 years ago

3/5 of a number is 21. Find the number.

Mathematics

1 answer:

raketka [301]3 years ago

7 0

Answer:

12.6

Step-by-step explanation:

multiply 3/5 by 21

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9th grade math I don’t understand

harkovskaia [24]

Do you have to keep going or only just one more number it seems to be going by 2’s 4,6,8,10,12 but I’m a little confused since it says it’s 9th grade work

4 0

3 years ago

A pitcher holds 3 liters of lemonade. If the contents of the pitcher are equally divided among 8 people, how much lemonade will

igomit [66]

Answer:

0.375 litres

Step-by-step explanation:

Given that:

Total amount of lemonade held by pitcher = 3 litres

Number of people in which lemonade is to be given equally = 8

Amount of Lemonade received by each person will be:

Total amount of lemonade / number of persons

3 litres / 8

= 0.375 litres

Each person receives 0.375 litres of lemonade

8 0

2 years ago

Please help with the questions in the image

iren2701 [21]

Step-by-step explanation:

This seems to be calculus 1.

Question a

We have $-2x^3 + 5x^2 + 9$

m = slope = derivative

Find the derivative / slope of $-2x^3 + 5x^2 + 9$

We do this by differentiating the polynomials. There are a few methods to do this but I am going to use the power rule, which we multiply the constant by the exponent on the variable and subtract one from the exponent.

$\frac{d}{dx}(-2x^3 + 5x^2 + 9)$

$-6x^2 + 10x$

$m = -6x^2 + 10x$ when x = a

Now that we have this information, we can answer question b

Question b

The tangent line for Point (1, 12)

First find the slope by using our derivative.

$m = -6x^2 + 10x$

$m = -6(1)^2 + 10(1)$

$m = -6 + 10x$

$m = 4$

Now that we have our slope, use point slope form to find our tangent line

$y - 12 = 4(x - 1)$

$y(x) = 4x + 8$

Now lets do the same for the Point (2, 13)

Find the slope at the point.

$m = -6x^2 + 10x$

$m = -6(2)^2 + 10(2)$

$m = -24 + 10$

$m = -4$

Now find the tangent line using point slope form of a line.

$y(x) - 13 = -4(x - 2)$

$y(x) = -4x + 21$

Now graph the lines, which I have done and you can see by viewing the image I have attached.

6 0

3 years ago

A bicycle rider increases his speed from 5 m/s to 15 m/s in 10 seconds

valentina_108 [34]

To find the acceleration of the bicycle rider, we are going to use the acceleration formula: $a= \frac{v_{f}-v_{i}}{t}$
where
$a$ is the acceleration
$v_{i}$ is the initial speed
$v_{f}$ is the final speed
$t$ is the time

We know from our problem that increases his speed from 5 m/s to 15 m/s in 10 seconds, so his initial speed is 5 m/s and his final speed is 15 m/s; therefore, $v_{i}=5$ , $v_{f}=15$ , and $t=10$ . Lets replace those values in our formula:
$a= \frac{v_{f}-v_{i}}{t}$
$a= \frac{15-5}{10}$
$a= \frac{10}{10}$
$a=1$

We can conclude that the acceleration of the bicycle rider 1 m/s^2

4 0

3 years ago

Need help with this problem please !!

Harrizon [31]

Answer:

Step-by-step explanation:

30y x 2 = 60y

3 0

3 years ago

Read 2 more answers