Melody

Hannah please tone your enthusiasm down just a bit.

Please don't answer questions when you do not have a clue

and please limit your social posts to maybe one a day.  

Consider the polynomial P(x) = x^4 - 3x^3 + 5x^2 - 7x + 9. Let its four roots be a, b, c, d.

Evaluate the expression (a + b + c)(a + b + d)(a + c + d)(b + c + d).

The sum of all the roots is  3/1 = 3

so the expression can be changed to

(3-d)(3-c)(3-b)(3-a)

now expand and then use Vieta's formulas to solve

Here is a simple little site that I like.

Put the numbers in and it will spit our your answer.

Firstly, this is not really the sum of 1 sequence, it is the sum of 2 sequences

\(1^2+3^2+5^2+ .......\\ 2.5^2+2.7^2+2.9^2......\\ S_{20}=1^2+3^2+5^2+ .......+19^2\quad+ \quad 2.5^2+2.7^2+2.9^2......+4.3^2\)

I suppose I could just calculate the answer.

\(S_{20}=1330+118.9 = 1448.9\\ A=1448.9/20=72.445\)

Doesn't look like any of those answers to me.

Well you have your answer :)

Thanks Hannah,

You didn't forget Cal,  Now you have given me 2 cakes.  Just as well that they are virtual :)

Does 71+71+38 = 180?

Hint:

The angle sum of a triangle is 180 degrees

Thanks Hannah.  I shall eat it with relish.  You and others on the forum can help me polish it off.   

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