Answer should be c hope it helps
Answer:
1
Step-by-step explanation:
when you multiply an complex number by its multiplicatuive identity, in case 4+8i, you would multiply both the top and the bottom by 4-8i which is actually the value one since we cannot actually change the whole value of the number. By multiplying it by 1 and we get the same value without the imaginary number
(sorry if this doesn't make sense but I hope it helps)
about that did you forget to put -4 + 8i just to make sure about it because I am not sure if you forget it or not just making sure
Answer:
a) Var[z] = 1600
D[z] = 40
b) Var[z] = 2304
D[z] = 48
c) Var[z] = 80
D[z] = 8.94
d) Var[z] = 80
D[z] = 8.94
e) Var[z] = 320
D[z] = 17.88
Step-by-step explanation:
In general
V([x+y] = V[x] + V[y] +2Cov[xy]
how in this problem Cov[XY] = 0, then
V[x+y] = V[x] + V[y]
Also we must use this properti of the variance
V[ax+b] = 
V[x]
and remember that
standard desviation = ![\sqrt{Var[x]}](https://tex.z-dn.net/?f=%5Csqrt%7BVar%5Bx%5D%7D)
a) z = 35-10x
Var[z] = 
Var[x] = 100*16 = 1600
D[z] = 
= 40
b) z = 12x -5
Var[z] = 
Var[x] = 144*16 = 2304
D[z] = 
= 48
c) z = x + y
Var[z] = Var[x+y] = Var[x] + Var[y] = 16 + 64 = 80
D[z] = 
= 8.94
d) z = x - y
Var[z] = Var[x-y] = Var[x] + Var[y] = 16 + 64 = 80
D[z] = = 8.94
e) z = -2x + 2y
Var[z] = 4Var[x] + 4Var[y] = 4*16 + 4*64 = 320
D[z] = 
= 17.88
Answer:
x + 150 deg = 180deg (being co-interior angles)
:. x = 30 deg
2. y^2 + 7= 32 ( opposite sides of parallelogram are equal)
or, y^2 = 25
or y^2 = 5^2
: . y = 5
3. k= 2y^2 ( opposite sides of parallelogram are equal)
or, k = 2× 5^2
: . k = 50
Multiply 8 the numerator and denominator to the second one.
12/1
8(12/1)
96/8
Now they have the same denominators.
