hey, I'm not sure about this answer, but I think it's true, sorry
m(2g+5mk)
Answer:
- (2x + 5)/(x - 9)
- 3. quantity 2 x plus 5 over x minus 9
Step-by-step explanation:
Quantity 2 x squared plus 13 x plus 20 all over x squared minus 5 x minus 36
- (2x² + 13x + 20)/(x² -5x - 36) =
- (2x²+ 5x + 8x + 20)/(x² - 9x + 4x -36)=
- (2x + 5)(x + 4)/(x - 9)(x + 4) =
- (2x + 5)/(x - 9)
Correct option is option 3
55
To start to solve this problem we start by observing what information there is. We need y, to find y we have to know x. We need x to find y because all the angles in a triangle add up to 180. If we find x we can subtract the angles we know and get y. To find x we look and see that it is on a straight line, and on the other side of the line is 100. We know that a straight line is 180 degrees so we subtract 100 from 180 to get x. We now know x is 80, so now we minus 89 and 45 from 180. We get 55. This means that y is 55.
Hope this helps! Please make me the brainliest, it’s not necessary but appreciated, I put a lot of effort and research into my answers. Have a good day, stay safe and stay healthy.
Adding 2 to each value of the random variable
makes a new random variable
. Its mean would be
![E[X+2]=E[X]+E[2]=E[X]+2](https://tex.z-dn.net/?f=E%5BX%2B2%5D%3DE%5BX%5D%2BE%5B2%5D%3DE%5BX%5D%2B2)
since expectation is linear, and the expected value of a constant is that constant.
is the mean of
, so the new mean would be
![E[X+2]=10+2=12](https://tex.z-dn.net/?f=E%5BX%2B2%5D%3D10%2B2%3D12)
The variance of a random variable
is
![V[X]=E[X^2]-E[X]^2](https://tex.z-dn.net/?f=V%5BX%5D%3DE%5BX%5E2%5D-E%5BX%5D%5E2)
so the variance of
would be
![V[X+2]=E[(X+2)^2]-E[X+2]^2](https://tex.z-dn.net/?f=V%5BX%2B2%5D%3DE%5B%28X%2B2%29%5E2%5D-E%5BX%2B2%5D%5E2)
We already know
, so simplifying above, we get
![V[X+2]=E[X^2+4X+4]-12^2](https://tex.z-dn.net/?f=V%5BX%2B2%5D%3DE%5BX%5E2%2B4X%2B4%5D-12%5E2)
![V[X+2]=E[X^2]+4E[X]+4-12^2](https://tex.z-dn.net/?f=V%5BX%2B2%5D%3DE%5BX%5E2%5D%2B4E%5BX%5D%2B4-12%5E2)
![V[X+2]=(V[X]+E[X]^2)+4E[X]-140](https://tex.z-dn.net/?f=V%5BX%2B2%5D%3D%28V%5BX%5D%2BE%5BX%5D%5E2%29%2B4E%5BX%5D-140)
Standard deviation is the square root of variance, so
.
![\implies V[X+2]=(9+10^2)+4(10)-140=9](https://tex.z-dn.net/?f=%5Cimplies%20V%5BX%2B2%5D%3D%289%2B10%5E2%29%2B4%2810%29-140%3D9)
so the standard deviation remains unchanged at 3.
NB: More generally, the variance of
for
is
![V[aX+b]=a^2V[X]+b^2V[1]](https://tex.z-dn.net/?f=V%5BaX%2Bb%5D%3Da%5E2V%5BX%5D%2Bb%5E2V%5B1%5D)
but the variance of a constant is 0. In this case,
, so we're left with
, as expected.
Answer:
$10.15
Step-by-step explanation:
68.15 - 58 = 10.15