They are not all squares because a rhombus has all sides of equal length, but NO right angles. A square is a rhombus WITH right angles.
Hope that clears things up.
Answer:12/5
Step-by-step explanation:
Step-by-step explanation:
First I do it as separate equations 2x-7=0 and 5x+3=0. In this equation you get two answers so you first answer 2x-7=0
2x-7=0
+7 +7
2x=7
/2 /2
x=7/2
Then do 5x+3=0
-3 -3
5x=-3
/5 /5
x= -3/5
Then you can check by putting them back in.
Answer:
Step-by-step explanation:
We have by definition
![Cov(X,Y) = E[(x – M_x)(Y – M_y)]](https://tex.z-dn.net/?f=Cov%28X%2CY%29%20%3D%20E%5B%28x%20%E2%80%93%20M_x%29%28Y%20%E2%80%93%20M_y%29%5D)
where Mx and My are means of X and Y respectively
a) ![E[(x – M_x)(Y – M_y)]\\= E(x,y) - E(x,My)-E(y,Mx)+M_x M_y\\=E(x,y) -E(x) M_y -E(y) M_x +M_x M_y\\=E(x,y)-M_x M_y-M_x M_y+M_x M_y\\=E(x,y)-M_x M_y](https://tex.z-dn.net/?f=E%5B%28x%20%E2%80%93%20M_x%29%28Y%20%E2%80%93%20M_y%29%5D%5C%5C%3D%20E%28x%2Cy%29%20-%20E%28x%2CMy%29-E%28y%2CMx%29%2BM_x%20M_y%5C%5C%3DE%28x%2Cy%29%20-E%28x%29%20M_y%20-E%28y%29%20M_x%20%2BM_x%20M_y%5C%5C%3DE%28x%2Cy%29-M_x%20M_y-M_x%20M_y%2BM_x%20M_y%5C%5C%3DE%28x%2Cy%29-M_x%20M_y)
b) Since right side inside expectation is commutative, we get cov(x,y) = cov (y,x)
c) 
d) 
f) Var(x+y) = 
Expanding inside we get
=
Answer:
1. x=1
2. x=-1
3. No solution
4. x=2
5. x= -6
Step-by-step explanation:
