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2 years ago

Help anyone please.................................

Mathematics

1 answer:

Helen [10]2 years ago

5 0

Answer:

- 3y

Step-by-step explanation:

$-\sqrt{9y^{2} } =-(9)^{\frac{1}{2} } (y)^{\frac{2}{2} } =-\sqrt{9} (y)^{1} =-3y$

Hope this helps

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for the following two numbers, find two factors of the first number such that their product is the first number and their sum is

zepelin [54]

You can make some algebraic equations and solve it.
The first would be:
$x \times y = - 21$
The second would be
$x + y = - 4$
You can then rearrange the second into
$x = - 4 - y$
And subsitute it into the first like so:
$( - y - 4) \times y = - 21$
After that, distribute the y into the parantheses.
${ - y}^{2} - 4y = - 21$
Subtract the 21 on both sides and multiply by -1 on both sides:
${ - y}^{2} - 4y + 21 \\ {y}^{2} + 4y - 21$
You then can factor it into:
$(y + 3) \times (y - 7) = 0$
With Zero Product Property, we can determine y to be either -3 and 7. Since the variables are interchangable, you can say the same about x, just that whatever x is, y must be the other value.

Thus, the answer is 7 and -3.

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3 years ago

What Force would be needed to extend a spring with a spring constant k=7 N/m that extends<br>0.3m?

vladimir2022 [97]

Answer:

Force = - 2.1 Newton

Step-by-step explanation:

According to question ,

The value of Spring constant , K = 7 N/m Newton per meter

And the spring is extended up to 0.3 meter

The Force experience on the spring is calculated from the Hook's Law

<u>The principal state that , the force applied on spring to extend or compress the spring to some distance is proportion to that distance. </u>

Let the force be F

So, F = - K X

where K is spring constant and X is its displacement

Negative sign shows displacement of spring once it is stretched

And K is spring constant

So ,Force = ( - ) 7 × 0.3

I.e Force = - 2.1 Newton Answer

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3 years ago

Please help domain/range and eqation

Elena-2011 [213]

Domain: (infinity, 4]
range: [-6, infinity)

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3 years ago

THIS IS A TEST AND I REALLY NEED HELP SO CAN YALL HELP ME ASAP

Ivanshal [37]

Step-by-step explanation:

a. x = 30° (180-70-80)

b. <FGA = 80°

c. vertical angles

4 0

3 years ago

In triangle △ABC, ∠ABC=90°,

makvit [3.9K]

<h3>Answer: As a fraction, HC is 21/4 units long</h3><h3>In decimal form, HC is 5.25 units long.</h3>

==============================================

Work Shown:

Let x = HC and y = BH

AH = 12-x since AH = 12-HC and x = HC

---------------

See the attached drawing below. The altitude BH forms three similar triangles which makes the proportion below possible

HC/BH = BH/AH

x/y = y/(12-x) ... substitution

x(12-x) = y^2 ... cross multiply

y^2 = -x^2+12x

note how I isolated y^2 instead of y. We will use this equation later.

---------------

Focus on triangle AHB. Use the pythagorean theorem

(BH)^2 + (AH)^2 = (AB)^2

(y)^2 + (12-x)^2 = (9)^2

y^2 + 144-24x+x^2 = 81

-x^2+12x + 144-24x+x^2 = 81 ... replace y^2 with -x^2+12x

-x^2+12x + 144-24x+x^2-81 = 0

-12x + 63 = 0

-12x = -63

x = -63/(-12)

x = 5.25 <<-- answer in decimal form

x = 5 + 0.25

x = 5 + 1/4

x = 20/4 + 1/4

x = 21/4 <<-- answer as a fraction

3 0

3 years ago