Answer:
![x=2+\frac{1}{2}\sqrt[]{21}](https://tex.z-dn.net/?f=x%3D2%2B%5Cfrac%7B1%7D%7B2%7D%5Csqrt%5B%5D%7B21%7D)
or

Step-by-step explanation:

Add 21 on both sides.


a=4
b=-16
c=-5
![x=\frac{-b\frac{+}{}\sqrt[]{b^2-4ac} }{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%20%20%7D%7B2a%7D)
![x=\frac{-(-16)\frac{+}{}\sqrt[]{(-16)^2-4(4)(-5)} }{2(4)}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-%28-16%29%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B%28-16%29%5E2-4%284%29%28-5%29%7D%20%20%7D%7B2%284%29%7D)
![x=\frac{16\frac{+}{}\sqrt[]{256+80} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B256%2B80%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}\sqrt[]{336} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B336%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}\sqrt[]{2^2*2^2*21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B2%5E2%2A2%5E2%2A21%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}2*2\sqrt[]{21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D2%2A2%5Csqrt%5B%5D%7B21%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}4\sqrt[]{21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D4%5Csqrt%5B%5D%7B21%7D%20%20%7D%7B8%7D)
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![x=\frac{16}{8}+\frac{4\sqrt[]{21}}{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%7D%7B8%7D%2B%5Cfrac%7B4%5Csqrt%5B%5D%7B21%7D%7D%7B8%7D)
![x=2+\frac{1}{2}\sqrt[]{21}](https://tex.z-dn.net/?f=x%3D2%2B%5Cfrac%7B1%7D%7B2%7D%5Csqrt%5B%5D%7B21%7D)
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![x=\frac{16}{8}-\frac{4\sqrt[]{21}}{8}\\x=2-\frac{1}{2}\sqrt{{21}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%7D%7B8%7D-%5Cfrac%7B4%5Csqrt%5B%5D%7B21%7D%7D%7B8%7D%5C%5Cx%3D2-%5Cfrac%7B1%7D%7B2%7D%5Csqrt%7B%7B21%7D)
Question has missing details (Full question below)
Measurement error that is continuous and uniformly distributed from –3 to +3 millivolts is added to a circuit’s true voltage. Then the measurement is rounded to the nearest millivolt so that it becomes discrete. Suppose that the true voltage is 219 millivolts. What is the mean and variance of the measured voltage
Answer:
Mean = 219
Variance = 4
Step-by-step explanation:
Given
Let X be a random variable measurement error.
X has a discrete uniform distribution as follows
a = 219 - 3 = 216
b = 219 + 3 = 222
Mean or Expected value is calculated as follows;
E(x) = ½(216+222)
E(x) = ½ * 438
E(x) = 219
Variance is calculated as follows;
Var(x) = ((b-a+1)²-1)/12
Var(x) = ((222-216+1)²-1)/12
Var(x) = (7²-1)/12
Var(x) = 48/12
Var(x) = 4
Answer:
Postitive numbers
Step-by-step explanation:
If you mean like half then 31?
Answer:
No
Step-by-step explanation:
it doesnt add up to 180 degrees