9514 1404 393
Answer:
B, D
Step-by-step explanation:
The quadratic expands to ...
(2n -1)² = (2n)² +2(2n)(-1) +(-1)² = 4n² -4n +1
The coefficients can be factored out of the sum, so ...
∑(4n²) = 4∑n² for example
The sum of 60 ones is 60:

So, the sum can be written as ...

_____
It appears that the key to choosing the correct answers is paying attention to signs.
Answer:
24/7
Step-by-step explanation:
A=77
A=l*w
l=2w+3
2w^2+3w=77
w=5.5
A=5.5l
/5.5
l=14
So 14*5.5
The answer to this would be D