3n-15/n-1=12

Solution for 3n-15/n-1=12 equation:

D( n )

n = 0

n = 0

n = 0

n in (-oo:0) U (0:+oo)

3*n-(15/n)-1 = 12 // - 12

3*n-(15/n)-12-1 = 0

3*n-15*n^-1-12-1 = 0

3*n^1-15*n^-1-13*n^0 = 0

(3*n^2-13*n^1-15*n^0)/(n^1) = 0 // * n^2

n^1*(3*n^2-13*n^1-15*n^0) = 0

n^1

3*n^2-13*n-15 = 0

3*n^2-13*n-15 = 0

DELTA = (-13)^2-(-15*3*4)

DELTA = 349

DELTA > 0

n = (349^(1/2)+13)/(2*3) or n = (13-349^(1/2))/(2*3)

n = (349^(1/2)+13)/6 or n = (13-349^(1/2))/6

n in { (13-349^(1/2))/6, (349^(1/2)+13)/6} 

n in { (13-349^(1/2))/6, (349^(1/2)+13)/6 }