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1 year ago

I forgot how to do this, can someone help me-

Mathematics

1 answer:

Artyom0805 [142]1 year ago

6 0

Step-by-step explanation:

1) x/20 = -9

By cross multiplication,

x = -180

2) -168 = -14k

k = -168/-14

k = 12

3) -5m = -50

m = 10

4) -320 = -20n

n = 16

5) -4 = x - 5

x = 1

6) -6(-8 + n) = -54

42 - 6n = -54

-6n = -54 -52

6n = 106

n = 17.6

7) 3(x - 9) = -3

3x - 27 = -3

3x = 24

x = 8

8) 9k + 3 = -78

9k = -81

k = -9

9)4 + (n/4) = 8

By taking LCM,

16 + n/4 = 8

16 + n = 32

n = 16

10) -5r + 7 = -73

-5r = -80

r = 16

Hope it helps.

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Solve the system: 2x+6y=36 x+4y=20

Assoli18 [71]

Let's solve this problem step-by-step

Let's set:

2x + 6y = 36 -- equation 1

x + 4y = 20 -- equation 2

(equation 2) * 2

2x + 8y = 40 -- equation 3

(equation 3) - (equation 1)

2y = 4

y = 2 -- equation 4

Plug (equation 4)'s value of y into (equation 2)

x + 4(2) = 20

x = 20 - 8

x = 12

Thus x = 12 and y = 2

Let's check, by substituting these values

$2x + 6y = 36\\2(12)+6(2) = 36\\24+12=36\\36=36\\\\x+4y=20\\12+4(2)=20\\12+8=20\\20=20$

Answer: x = 12 and y = 2

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2 years ago

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Answer:

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Step-by-step explanation:

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9 * r = 81

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2 years ago

9(2w−y)=21w−9y Solve for y

valentinak56 [21]

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First you multiply the numbers in the parenthesis by 9

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3 years ago

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2 years ago

A rectangle is inscribed with its base on the x-axis and its upper corners on the parabola y = 5 − x 2 . What are the dimensions

kherson [118]

Answer:

A rectangle is inscribed with its base on the x-axis and its upper corners on the parabola

y=5−x^2. What are the dimensions of such a rectangle with the greatest possible area?

Width =

Height =

Width =√10 and Height $= \frac{10}{4}$

Step-by-step explanation:

Let the coordinates of the vertices of the rectangle which lie on the given parabola y = 5 - x² ........ (1)

are (h,k) and (-h,k).

Hence, the area of the rectangle will be (h + h) × k

Therefore, A = h²k ..... (2).

Now, from equation (1) we can write k = 5 - h² ....... (3)

So, from equation (2), we can write

$A =h^{2} [5-h^{2} ]=5h^{2} -h^{4}$

For, A to be greatest ,

$\frac{dA}{dh} =0 = 10h-4h^{3}$

⇒ $h[10-4h^{2} ]=0$

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Therefore, from equation (3), k = 5 - h²

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Hence,

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