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Mekhanik [1.2K]

3 years ago

11

If y varies directly with x and y = 16 when x = 4, find x when y = 8.

2 answers:

VladimirAG [237]3 years ago

7 0

Answer: X = 2

Step-by-step explanation:

Y & X

Y = KX

K = Y/X = 16/4 = 4

Y= 8

K =4

X=?

X = Y/K

X = 8/4 = 2

Luba_88 [7]3 years ago

5 0

Step-by-step explanation:

$Given: \\ y \: \alpha \: x \\ \therefore \: y = kx..(k = constant)..(1) \\ \\ let \: us \: substitute \: x = 4 \: and \: y = 16 \: \\ in \: equation \: (1)\\ \\ 16 = 4k \: \\ \implies \: k = \frac{16}{4} \\ \implies \: k = 4 \\ substituting \: k = 4 \: in \: equation \: \\ (1) \: we \: find : \\ y = 4x....(2) \\ now \: we \: need \: to \: find \: x \: when \: y = 8 \\ \therefore \: 8 = 4x \\ \implies \: x = \frac{8}{4} \\ \huge \orange{ \boxed{\implies \: x = 2}}$

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3 years ago

You have a wire that is 20 cm long. You wish to cut it into two pieces. One piece will be bent into the shape of a square. The o

Aleksandr [31]

Answer:

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Step-by-step explanation:

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Given that the length of the wire is 20 cm.

According to the problem,

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Putting the value of s

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Differentiating with respect to r

$\frac{dA}{dr}= \frac{2\pi r(4+\pi)}{4} -5\pi$

Again differentiating with respect to r

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$\frac{dA}{dr}=0$

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zhuklara [117]

Answer:

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