hi i have a small problem.(adsbygoogle = window.adsbygoogle || []).push({});

i need to prove that these two expressions are equal :

(n*Sum{i=1,n}Xi*Yi - Sum{i=1,n}Xi*Sum{i=1,n}Yi)/(n*Sum{i=1,n}(Xi)^2 - (Sum{i=1,n}Xi)^2)

and the expression :

(Sum{i=1,n}(Xi)*(Xi*Y^ - Yi*X^))/(Sum{i=1,n}((Xi)^2 - (x^)^2 ))

here is x^ and y^ the middle values of x and y .

i need to transpose the one expression over in the other. But i cant get this to work.

Can someone help me?

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# A sum problem

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