She used the associative property which should only be used with positive numbers (sorry if it isn't the answer you're looking for)
For this case we have the following expression:

We must find the value of the expression when:

Substituting we have:

Finally, the value of the expression is:

ANswer:

Answer:
a)
b) ![P(X> 2)=1-P(X\leq 2)=1-[0.0211+0.0995+0.211]=0.668](https://tex.z-dn.net/?f=P%28X%3E%202%29%3D1-P%28X%5Cleq%202%29%3D1-%5B0.0211%2B0.0995%2B0.211%5D%3D0.668)
c)
Step-by-step explanation:
1) Previous concepts
The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".
2) Solution to the problem
Let X the random variable of interest, on this case we now that:
The probability mass function for the Binomial distribution is given as:
Where (nCx) means combinatory and it's given by this formula:
Part a
Part b
![P(X> 2)=1-P(X\leq 2)=1-[P(X=0)+P(X=1)+P(X=2)]](https://tex.z-dn.net/?f=P%28X%3E%202%29%3D1-P%28X%5Cleq%202%29%3D1-%5BP%28X%3D0%29%2BP%28X%3D1%29%2BP%28X%3D2%29%5D)
![P(X> 2)=1-P(X\leq 2)=1-[0.0211+0.0995+0.211]=0.668](https://tex.z-dn.net/?f=P%28X%3E%202%29%3D1-P%28X%5Cleq%202%29%3D1-%5B0.0211%2B0.0995%2B0.211%5D%3D0.668)
Part c
Answer:
70
Step-by-step explanation:
Take the absolute value of both numbers. In this case, -38 and 32. So 38 and 32.
Add: 38+32
70
I think I may be wrong
X+ y = 10
2x = 2y+4
2x/2 = 2/2y+4/2
x = y + 2
x+y = 10
y+2+y=10
2y + 2 = 10
2y +2-2 =10-2
2y = 8
2y/2 =8/2
y = 4
x + y =10
x + 4 =10
x +4-4 =10-4
x = 6
Check
2x = 2y +4
2(6) = 2(4) +4
12 = 8+4
12= 12