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3 years ago

Suppose a varies directly as b, and a=7 when b=2 find b when a =21

1 answer:

6 0

Because α varies directley to β
$\alpha = k \beta$
(k = constant)

α=7 when β=2
7= 2k
k= $\frac{7}{2}$

so when α=21
21= $\frac{7}{2}$ b
b= 6

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Multiply 3/7 by the reciprocal of -3/14

Alexandra [31]

Multiplying 3/7 by the reciprocal of -3/14,

$\frac{3}{7} \times \frac{14}{ - 3} \\ = \frac{1}{1} \times \frac{2}{ - 1} \\ = \frac{2}{ - 1} \\ = - 2$

Hope it helps!!

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3 years ago

Angle of depression from point a to point c

Arisa [49]

Answer:

32°

Step-by-step explanation:

90 - 58 = 32

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3 years ago

What is the approximate volume of a cylinder with a radius of 3 centimeters and a height of 4 centimeters?

Tema [17]

Answer:

113.04 cm

Step-by-step explanation:

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2 years ago

The thickness of a U.S. penny is 5.98 X 10-2 inch.

Aleksandr [31]

Answer: $1.495*10^8\ inches$

Step-by-step explanation:

For this exercise you have to remember the Product of powers property, which states that:

$(a^m)(a^n)=a^{(m+n)}$

Let be "x" the height in inches of a stack of $2.5*10^9$ pennies.

You know that the thickness of 1 pennie is $5.98*10^{-2}\ inches$ , then, you can write the following proportion:

$\frac{5.98*10^{-2}}{1}=\frac{x}{2.5*10^9}$

Solve for "x":

$(2.5*10^9)(\frac{5.98*10^{-2}}{1})=x\\\\x=14.95*10^7$

To express this height in Scientific notation the decimal point must be after the first digit, so you must move it one place to the left:

$x=1.495*10^8$

4 0

3 years ago

A park ranger hiked 3/4 mi to a lookout, another 5/7 mi to a bird's nest, and finally 5/14 mi to a campsite. How far did the par

dusya [7]

Answer:

2 miles and 88 yards.

Step-by-step explanation:

4 has 2*2 as prime factors

5 is prime

10 has 2 and 5 as prime factors

Thus, the lowest common denominator will be 2*2*5

3/4=15/20

3/5=12/20

7/10=14/20

Now that we have three fractions with the same denominator, we can add the numerators

15+12+14=41

So 41/20ths

That’s 2 and 1/20th

So the final answer is 2 miles and 88 yards! :)

7 0

3 years ago