Answer: Like terms are -7 and 2. Simplified version would be 7d-5.
Step-by-step explanation:
first you would distribute, so it would be 7(d-1)+2 = 7d-7+2. Combine like terms. The only like terms here are -7 and 2, so just basically subtract -7 from 2 and you would get -5. you can't do anything with 7d because there is no like term for it.
Answer: -1.7
Step-by-step explanation:
Given : Another home business has an average income of $1.200.00 per month with a standard deviation of $100.00.
i.e.
Let x represents the monthly income.
Since . 
For x= 1030 , we have
Hence, the required z-score = -1.7
Answer:
1920π
Step-by-step explanation:
First, you need to find the volume of the statue in terms of pi.
Volume of cylinder formula:
V=πr²h
V=π4²15
V=π16×15
V=240π
Then, you need to find the mass of the statue.
Mass:
Mass= density × volume
Mass=20×240π
Mass=4800π
Now, you need to find the volume. Since the sand has to weigh the same as the statue, the mass is going to stay the same. To find the volume you need to do:
V=mass of sand/density
V=4800π/2.5
That gives you your answer:
1920π
Note: I had to do the exact same problem on Khan Academy. This is right.
Answer:
E is not a subspace of 
Step-by-step explanation:
E is not a subspace of
In order to see this, we must find two points (a,b), (c,d) in E such that (a,b) + (c,d) is not in E.
Consider
(a,b) = (1,1)
(c,d) = (-1,-1)
It is easy to see that both (a,b) and (c,d) are in E since 1*1>0 and (1-)*(-1)>0.
But (a,b) + (c,d) = (1-1, 1-1) = (0,0)
and (0,0) is not in E.
By the way, it can be proved that in any vector space all sub spaces must have the vector zero.
