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3 years ago

2x-3y=-1 3x-4y=-1 giải hpt

Mathematics

1 answer:

bonufazy [111]3 years ago

8 0

Answer:

x = 1

Y = 1

Step-by-step explanation:

A. 3(2x-3y= - 1)

6x-9y=- 3

B. -2(3x-4y= - 1)

- 6x+8y=2

Add both equations:

(6x-9y= - 3) + (- 6x+8y=2)

-y= - 1

3x - 4(1) = - 1

3x-4= - 1

3x = 4 - 1

= 3/3 = 1

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Which of the k-values satisfy the following inequality?

Arte-miy333 [17]

6>2k+4
2>2k
1>k

k has to be less than 1

Answer: a) k=0

Hope this helps:)

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3 years ago

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Find the center and the radius of the circle with the equation: <br> x2+6x+y2+4y+12=0

Andrews [41]

Answer:

centre = (- 3, - 2) , radius = 1

Step-by-step explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k) are the coordinates of the centre and r is the radius

Given

x² + 6x + y² + 4y + 12 = 0 ( subtract 12 from both sides )

x² + 6x + y² + 4y = - 12

Use the method of completing the square on the x and y terms

add ( half the coefficient of the x/ y terms )² to both sides

x² + 2(3)x + 9 + y² + 2(2)y + 4 = - 12 + 9 + 4

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3 years ago

A species of beetles grows 32% every year. Suppose 100 beetles are released into a field. How many beetles will there be in 10 y

siniylev [52]

Given that a species of beetles grows 32% every year.

So growth rate is given by

r=32%= 0.32

Given that 100 beetles are released into a field.

So that means initial number of beetles P=100

Now we have to find about how many beetles will there be in 10 years.

To find that we need to setup growth formula which is given by

$A=P(1+r)^n$ where A is number of beetles at any year n.

Plug the given values into above formula we get:

$A=100(1+0.32)^n$

$A=100(1.32)^n$

now plug n=10 years

$A=100(1.32)^{10}=100(16.0597696605)=1605.97696605$

Hence answer is approx 1606 beetles will be there after 20 years.

Now we have to find about how many beetles will there be in 20 years.

To find that we plug n=20 years

$A=100(1.32)^{20}=100(257.916201549)=25791.6201549$

Hence answer is approx 25791 beetles will be there after 20 years.

Now we have to find time for 100000 beetles so plug A=100000

$A=100(1.32)^n$

$100000=100(1.32)^n$

$1000=(1.32)^n$

$log(1000)=n*log(1.32)$

$\frac{\log\left(10000\right)}{\log\left(1.32\right)}=n$

33.174666862=n

Hence answer is approx 33 years.

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4 years ago

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Answer:

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3 years ago

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3 years ago