The value of Z would be 225°
<h3>What is the angle at a point?</h3>
The angle at a point are angles that add up to 360°
Thus, X + Y + Z = 360°
X = 20°
Y = 135°
Then, Z = 360° - X - Y
Z = 360° - 20° + 135°
Z = 360° - 155°
Z = 205°
Therefore, the value of Z is 205°
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Answer:
Two solutions
Step-by-step explanation:
This is a quadratic equation in the form y = ax² + bx + c.
For quadratic equations, you can find solutions using the quadratic formula:
.
To find the number of solutions, <u>you only need what's inside the square root</u>. We call it the "<u>discriminant</u>" because lets us know the number of solutions without solving.

If b²- 4ac > 0, two solutions. (greater than)
If b²- 4ac < 0, no solutions. (less than)
If b²- 4ac = 0, one solution. (equal to)
y = ax² + bx + c
y = -3x² + x + 12
a = -3 b = 1 c = 12
<u>Substitute into the discriminant</u>
b²- 4ac
= 1² - 4(-3)(12)
= 1 - (-144)
= 145 > 0
b²- 4ac > 0 Discriminant greater than 0
Therefore, there are two solutions.
Answer:
D
Step-by-step explanation:
I'm not sure 100%
Answer:
The expected number of days until prisoner reaches freedom is 12 days
Step-by-step explanation:
From the given information:
Let X be the random variable that denotes the number of days until the prisoner reaches freedom.
We can evaluate E(X) by calculating the doors selected, If Y be the event that the prisoner selects a door, Then;
E(X) = E( E[X|Y] )
E(X) = E [X|Y =1 ] P{Y =1} + E [X|Y =2 ] P{Y =2} + E [X|Y =3 ] P{Y =3}
![E(X) = (2 + E[X])\dfrac{1}{2}+ (4 + E[X])\dfrac{3}{10}+ 1 (\dfrac{2}{10})](https://tex.z-dn.net/?f=E%28X%29%20%3D%20%282%20%2B%20E%5BX%5D%29%5Cdfrac%7B1%7D%7B2%7D%2B%20%284%20%2B%20E%5BX%5D%29%5Cdfrac%7B3%7D%7B10%7D%2B%201%20%28%5Cdfrac%7B2%7D%7B10%7D%29)
![E(X) = (2 + E[X])0.5+ (4 + E[X])0.3+ 0.2](https://tex.z-dn.net/?f=E%28X%29%20%3D%20%282%20%2B%20E%5BX%5D%290.5%2B%20%284%20%2B%20E%5BX%5D%290.3%2B%200.2)
Solving for E[X]; we get
E[X] = 12
The answer will be number 2