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3 years ago

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Suppose that x and y vary inversely, and x=30 when y=2. Find y when x=5

1 answer:

Sedbober [7]3 years ago

4 0

I don’t know- the first thing I would think is that x=15*y because 30=15*2

So that’s my thinking, which means that if x=5, then y=5/15 or 1/3 or as a decimal .33

However I’m not sure if that’s right- I hope it helps!

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Complementary angles sum up to equal 90 degrees. Find the measure of each angle in the figure below. Note that since the angles

laiz [17]

#1 and #2 both equal 30 or x=30

3 0

3 years ago

Is y – 2 = –5(x – 2) a linear function

PIT_PIT [208]

Answer:

Yes

Step-by-step explanation:

y-2=-5(x-2)

y=-3(x-2)

6 0

2 years ago

1/(x-1)x+1/x(x+1)+...+1/(x+9)(x+10)=11/12

nata0808 [166]

Notice that

$\dfrac1{(x-1)x} = \dfrac1{x-1} - \dfrac1x \\\\ \dfrac1{x(x+1)} = \dfrac1x - \dfrac1{x+1} \\\\ \vdots \\\\ \dfrac1{(x+9)(x+10)} = \dfrac1{x+9} - \dfrac1{x+10}$

That is, the <em>n</em>-th term (where <em>n</em> = -1, 0, 1, …, 9) in the sum on the left side has a partial fraction decomposition of

$\dfrac{1}{(x+n)(x+n+1)} = \dfrac1{x+n} - \dfrac1{x+n+1}$

and in the sum, some adjacent terms will cancel and leave you with

$\dfrac1{(x-1)x} + \dfrac1{x(x+1)} + \cdots + \dfrac1{(x+9)(x+10)} = \dfrac1{x-1} - \dfrac1{x+10} = \dfrac{11}{12}$

Now solve for <em>x</em>, bearing in mind that we cannot have <em>x</em> = 0, -1, -2, …, -10 :

$\dfrac1{x-1} - \dfrac1{x+10} = \dfrac{11}{12}$

Combine the fractions on the left side:

$\dfrac{(x+10)-(x-1)}{(x-1)(x+10)} = \dfrac{11}{(x-1)(x+10)} = \dfrac{11}{12}$

Then we must have

$(x-1)(x+10) = x^2 + 9x - 10 = 12 \implies x^2+9x-22 = (x+11)(x-2) = 0$

so that either <em>x</em> = 2 or <em>x</em> = -11.

4 0

3 years ago

Cost of pen:1.50 <br> markup:70%

Ira Lisetskai [31]

If by markup you mean discount then.....
1.5*0.07 = $0.105
That must be a very good pen ;D

3 0

3 years ago

Read 2 more answers

Solve for s.<br> Give an exact answer.<br> 63 – 4= 8(2+1/4s)

Sloan [31]

Answer:

s=5

Step-by-step explanation:

6s-4=8(2+1/4s)

6s-4=16+2s

4s-4=16

4s=20

s=5

7 0

3 years ago

Read 2 more answers