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:
(x−5y)(9x+8)
Step-by-step explanation:
9x^2−45yx+8x−40y
Do the grouping 9x^2−45yx+8x−40y=(9x^2−45yx)+(8x−40y), and factor out 9x in the first and 8 in the second group.
9x(x−5y)+8(x−5y)
Factor out common term x−5y by using distributive property.
(x−5y)(9x+8)
9514 1404 393
Answer:
a) <8.356, 9.959>
b) <-0.605, -1.663>
c) <-5.023, 2.9>
Step-by-step explanation:
Many calculators can perform polar ⇔ rectangular conversion. Attached is the result from one of them. Of course, you can also program a spreadsheet to do it. (The ATAN2( ) function is useful for finding the correct angle.)
If you want to do these calculations by hand, the conversion is ...
<r, θ> ⇒ <r·cos(θ), r·sin(θ)>
In the attached, the rectangular coordinates are shown as complex numbers. The imaginary component is the y-component of the vector.
You add 6240 to get from -6250 to -10 your welcome