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Mathematics

1 answer:

Anit [1.1K]3 years ago

4 0

B is the correct answer to this question

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Cound someone please help me on this, I'm stuck.

Katyanochek1 [597]

Negative exponents work like this:

$a^{-b}=\dfrac{1}{a^b}$

So, in order to evaluate a negative exponent, you simply have to invert the base, and then raise to the positive equivalent of the exponent.

As an example, here are the first three exercises:

$8^{-3}=\dfrac{1}{8^3}=\dfrac{1}{512}$

$(-4)^{-5}=\dfrac{1}{(-4)^5}=-\dfrac{1}{1024}$

$2k^{-4}=\dfrac{2}{k^4}$

You can work out the rest applying this logic.

5 0

3 years ago

The sum of the areas of two circles is 80 pi

katovenus [111]

The area of a circle is A = πr^2. We let A1 And A2 the areas of the circles and r1 and r2 the radius of each, respectivley.

A1 + A2 = 80π
Substitute the formula for the area,
π(r1)^2 + π (r2)^2 = 80π

From the statement, we know that r2=2(r1).

<span>π(r1)^2 + π (2 x r1)^2 = 80π
</span>We can cancel π, we will have

5 x (r1)^2 = 80
Thus,

r1 = 4 and r2 = 8

5 0

3 years ago

A helicopter leaves an airport and flies south at 180 mi/h. Thirty minutes later, an airplane leaves the airport and follows the

stira [4]

Answer:

36 minutes

Step-by-step explanation:

helicopter 1 is ahead of helicopter 2 by 90 miles

the difference in their speeds is 150 mph

90/150=3/5 of hour

3/5*60=36 minutes

8 0