(3n^2+2n-1)+(2n^2+n+9)=

Solution for (3n^2+2n-1)+(2n^2+n+9)= equation:

Simplifying
(3n2 + 2n + -1) + (2n2 + n + 9) = 0

Reorder the terms:
(-1 + 2n + 3n2) + (2n2 + n + 9) = 0

Remove parenthesis around (-1 + 2n + 3n2)
-1 + 2n + 3n2 + (2n2 + n + 9) = 0

Reorder the terms:
-1 + 2n + 3n2 + (9 + n + 2n2) = 0

Remove parenthesis around (9 + n + 2n2)
-1 + 2n + 3n2 + 9 + n + 2n2 = 0

Reorder the terms:
-1 + 9 + 2n + n + 3n2 + 2n2 = 0

Combine like terms: -1 + 9 = 8
8 + 2n + n + 3n2 + 2n2 = 0

Combine like terms: 2n + n = 3n
8 + 3n + 3n2 + 2n2 = 0

Combine like terms: 3n2 + 2n2 = 5n2
8 + 3n + 5n2 = 0

Solving
8 + 3n + 5n2 = 0

Solving for variable 'n'.

Begin completing the square.  Divide all terms by
5 the coefficient of the squared term: 

Divide each side by '5'.
1.6 + 0.6n + n2 = 0

Move the constant term to the right:

Add '-1.6' to each side of the equation.
1.6 + 0.6n + -1.6 + n2 = 0 + -1.6

Reorder the terms:
1.6 + -1.6 + 0.6n + n2 = 0 + -1.6

Combine like terms: 1.6 + -1.6 = 0.0
0.0 + 0.6n + n2 = 0 + -1.6
0.6n + n2 = 0 + -1.6

Combine like terms: 0 + -1.6 = -1.6
0.6n + n2 = -1.6

The n term is 0.6n.  Take half its coefficient (0.3).
Square it (0.09) and add it to both sides.

Add '0.09' to each side of the equation.
0.6n + 0.09 + n2 = -1.6 + 0.09

Reorder the terms:
0.09 + 0.6n + n2 = -1.6 + 0.09

Combine like terms: -1.6 + 0.09 = -1.51
0.09 + 0.6n + n2 = -1.51

Factor a perfect square on the left side:
(n + 0.3)(n + 0.3) = -1.51

Can't calculate square root of the right side.

The solution to this equation could not be determined.