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3 years ago

14

The length of a rectangular room is 4 feet longer than twice the width. if the room's perimeter is 200 feet, what are the room's

dimensions?

2 answers:

Lera25 [3.4K]3 years ago

7 0

P = 2(L + W)
P = 200
L = 2W + 4

200 = 2(2W + 4 + W)
200 = 2(3W + 4)
200 = 6W + 8
200 - 8 = 6W
192 = 6W
192/6 = W
32 = W <== the width is 32 ft

L = 2W + 4
L = 2(32) + 4
L = 64 + 4
L = 68 <=== the length is 68 ft

Dovator [93]3 years ago

7 0

32 = w ----- the width is 32 feet

68 = L ------ the length is 68 feet

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Step-by-step explanation:

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130 days is the half-life of the given radioactive element.

For half life,

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$\rightarrow -ln|2|=-\lambda \times 130$

$\rightarrow \lambda= \frac{-ln|2|}{-130}$

$\rightarrow \lambda= \frac{ln|2|}{130}$

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$\Rightarrow ln|{{\frac {80}{100}|=-\frac{ln2}{130}t$

$\Rightarrow ln|{{ {80}|-ln|{100}|=-\frac{ln2}{130}t$

$\Rightarrow t=\frac{ln|80|-ln|100|}{-\frac{ln|2|}{130}}$

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$\Rightarrow t\approx 42$

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3 years ago

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(B) (A)

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