Answer:
<h2>Cubing both sides of an equation is reversible.</h2>
Step-by-step explanation:
Squaring both sides of an equation is irreversible, because the square power of negative number gives a positive result, but you can't have a negative base with a positive number, given that the square root of a negative number doesn't exist for real numbers.
In case of cubic powers, this action is reversible, because the cubic root of a negative number is also a negative number. For example
![\sqrt[3]{x} =-1](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7Bx%7D%20%3D-1)
We cube both sides
![(\sqrt[3]{x} )^{3} =(-1)^{3} \\x=-1](https://tex.z-dn.net/?f=%28%5Csqrt%5B3%5D%7Bx%7D%20%29%5E%7B3%7D%20%3D%28-1%29%5E%7B3%7D%20%5C%5Cx%3D-1)
If we want to reverse the equation to the beginning, we can do it, using a cubic root on each side
![\sqrt[3]{x}=\sqrt[3]{-1} \\\sqrt[3]{x}=-1](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7Bx%7D%3D%5Csqrt%5B3%5D%7B-1%7D%20%5C%5C%5Csqrt%5B3%5D%7Bx%7D%3D-1)
There you have it, cubing both sides of an equation is reversible.
I would half 198, get
99 and add a 0, this is how you multiply by 5 in your head
198*5 = 990
990 + 200 = 1190 - 2
= 1188
Alternatively we can round 198 to 200: then multiply by 6
200*6 = 1200
Then We subtract the 6 "2's" that we added
1200 - 12 = 1188
The expression for this is:
(6*200) - (6 * 2)
As the problem states, to solve this, we are going to use the equation
where
is the loudness in dB
is the intensity of a sound
<span>is the minimum intensity detectable by the human ear
</span>
We know for our problem that
; we also now that the minimum intensity detectable by the human ear is
, so
. Lets replace those values in our equation to find
:
Qe can conclude that since the explosion is under 100dB, it does not violates the regulation of the town. We used tow physical values to calculate the answer: the intensity of the sound of the explosion,
, and the minimum intensity detectable by the human ear
.
Answer: The correct option is d
Step-by-step explanation:
Standard error measures how far the sample mean is from the population mean.
The formula for determining the standard error of the distribution of difference in means is expressed as
Standard error = √(s1²/n1 + s2²/n2)
where
s1 = sample 1 standard deviation
s2 = sample 2 standard deviation
n1 = number of samples 1
n2 = number of samples 2
From the information given
s1 = 2 pounds
n1 = 43 pounds
s2 = 1.7 pounds
n2 = 40 pounds
Standard error = √(2²/43 + 1.7²/40)
Answer: 1 f of 3 = 2 f of 2 = negative
Step-by-step explanation:
