(6n^2+1)/(2n-2) - (3n^2+5n)/(n+3)
=(6n^2+1)*(n+3) - (3n^2+5n)*(2n-2) ) / ( (2n-2)*(n+3) )
= (14n^2 + 11n + 3 ) / ( 2n^2 + 4n - 6 )
= ( 14 + 11/n + 3/n^2 ) / ( 2 + 4/n - 6/n^2 )
Die Brüche gehen alle gegen 0, also ist der
Grenzwert 14 / 2 = 7
lim(n->unendlich)=(6n^2+1)/(2n-2) - (3n^2+5n)/(n+3) = 7