5n^2-4n-1=(3)-7

Solution for 5n^2-4n-1=(3)-7 equation:

Simplifying
5n2 + -4n + -1 = (3) + -7

Reorder the terms:
-1 + -4n + 5n2 = (3) + -7
-1 + -4n + 5n2 = 3 + -7

Combine like terms: 3 + -7 = -4
-1 + -4n + 5n2 = -4

Solving
-1 + -4n + 5n2 = -4

Solving for variable 'n'.

Reorder the terms:
-1 + 4 + -4n + 5n2 = -4 + 4

Combine like terms: -1 + 4 = 3
3 + -4n + 5n2 = -4 + 4

Combine like terms: -4 + 4 = 0
3 + -4n + 5n2 = 0

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

Divide each side by '5'.
0.6 + -0.8n + n2 = 0

Move the constant term to the right:

Add '-0.6' to each side of the equation.
0.6 + -0.8n + -0.6 + n2 = 0 + -0.6

Reorder the terms:
0.6 + -0.6 + -0.8n + n2 = 0 + -0.6

Combine like terms: 0.6 + -0.6 = 0.0
0.0 + -0.8n + n2 = 0 + -0.6
-0.8n + n2 = 0 + -0.6

Combine like terms: 0 + -0.6 = -0.6
-0.8n + n2 = -0.6

The n term is -0.8n.  Take half its coefficient (-0.4).
Square it (0.16) and add it to both sides.

Add '0.16' to each side of the equation.
-0.8n + 0.16 + n2 = -0.6 + 0.16

Reorder the terms:
0.16 + -0.8n + n2 = -0.6 + 0.16

Combine like terms: -0.6 + 0.16 = -0.44
0.16 + -0.8n + n2 = -0.44

Factor a perfect square on the left side:
(n + -0.4)(n + -0.4) = -0.44

Can't calculate square root of the right side.

The solution to this equation could not be determined.