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2 years ago

0=x^2+4x+1. Khan academy

1 answer:

34kurt2 years ago

4 0

Now, to find 'x' you will apply the Null Factor Law. This means you will now let 'x' = 0, and simply move the -2 over to the other side to find your answer. Note: since we are using a perfect square, x will only have one value since there is only one answer (x-2) in the brackets, meaning in this case we can ignore the exponent (as the answers will be the same). If there was more than one answer in the bracket (e.g. (x-4) and (x-6)), then we would apply Null Factor Law to both brackets and solve for x.

(x−2)=5

x=5+2

x=7

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After heating up in a teapot, a cup of hot water is poured at a temperature of 204°F.

laila [671]

Answer:

Question 1: 0.081 min⁻¹

Question 2: 168ºF

Explanation:

The missing equation is:

$T=T_a+(T_0-T_a)e^{-kt}$

You are given:

Ta = the temperature surrounding the object = 73ºF
T₀ = the initial temperature of the object = 204ºF
t = 2.5 min
T after 2.5 min = 180ºF

Question 1: Find the the value of k.

Substitute the data into the equation and solve for k:

$180\º=73\º+(204\º-73\º)e^{-k\cdot 2.5min}\\ \\ 107\º=131\ºe^{-k\cdot 2.5min}\\\\-k\cdot 2.5min=\ln (107/131)\\\\k=0.081min^{-1}$

Question 2: Find the Fahrenheit temperature of the cup of water, to the nearest degree, after 4 minutes.

Subsititute into the formula and compute:

$T=73\ºF+(204\ºF-73\ºF)e^{-0.081min^{-1}\times 4min}\\ \\ T=73\ºF+(131\ºF)(0.72325024)\\\\T=168\ºF$

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3 years ago

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kotegsom [21]

Answer:

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Step-by-step explanation:

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2 years ago

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2 years ago

Ms. Lynch has 21 coins in nickels and dimes.

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Answer:

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1 year ago

What is 3,101 divided by 16 as a decimal please help

Amanda [17]

Answer:

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Step-by-step explanation:

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