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3 years ago

The value of y varies directly with x, and y=28 when x=7. Find y when x=4 by first finding k.

1 answer:

7 0

Direct proportionality is the type of proportionality where an increase in one quantity or variable causes a corresponding increase in another quantity.
Therefore; y varies directly as x
Hence; y α x
y =k x where k is a constant
if y= 28 and x = 7 , then k = 28/4 =4
hence, y = 4 k
when x = 4, then y= 16

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What is the GCF of 28a^3 b and 16ab ? <br><br> A)4ab<br> B)4a3b<br> C)28ab<br> D)112a3b2

N76 [4]

28a⁴b: 2 · 2 · 7 · a · a · a · a · b
16ab: 2 · 2 · 2 · 2 · a · b

GCF(28a⁴b, 16ab) = 4ab

The answer is A.

7 0

3 years ago

If Diana walks forward and her angle looking to the top of the building changes to 40°, how much closer is she to the building?

elena55 [62]

The closer Diana gets to the building, the smaller the angle becomes

Diana is 17.6 feet closer to the building

<h3>How to calculate the distance from the building</h3>

To calculate the distance between her and the building, we make use of the following tangent ratio

$\tan(\theta) = \frac{h}{d}$

Where:

$\theta = 40^o$
h represents the height of the building; h = 130
d represents the distance from the building

So, we have:

$\tan(40) = \frac{130}{d}$

Make d the subject

$d = \frac{130}{\tan(40)}$

Evaluate tan(40)

$d = \frac{130}{0.8391}$

$d = 154.93$

Initially, Diana is at a distance of 172.53.

The difference in both distance is:

$\Delta d = 172.53 - 154.93$

$\Delta d = 17.6$

Hence, Diana is 17.6 feet closer to the building

Read more about trigonometry ratios at:

brainly.com/question/4326804

7 0

1 year ago

An online shopping club has 10,000 members when it charges $7 per month for membership. For each $1 monthly

Sonja [21]

Answer:

The function that can be used in the online shopping club about its monthly revenue is:

$R = -400x^{2} +7200x+70000$

Step-by-step explanation:

First, we're gonna take into account the different values we have in the exercise:

10,000 members
$7 per month for membership
Loses of 400 members by each $1 monthly increase

How the variable $x$ represents the price increase, we can do the formula below:

$(10000 - 400x) * (7+x)$

In this formula, we represent in the first part that by each 1 in the variable $x$ , the total of members will be reduced in 400, in the second part, we mention that at the same time, the membership fee will be increased in the same value of $x$ . Now we must simplify this function: