2z^2+4z+7=0

Solution for 2z^2+4z+7=0 equation:

Simplifying
2z2 + 4z + 7 = 0

Reorder the terms:
7 + 4z + 2z2 = 0

Solving
7 + 4z + 2z2 = 0

Solving for variable 'z'.

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

Divide each side by '2'.
3.5 + 2z + z2 = 0

Move the constant term to the right:

Add '-3.5' to each side of the equation.
3.5 + 2z + -3.5 + z2 = 0 + -3.5

Reorder the terms:
3.5 + -3.5 + 2z + z2 = 0 + -3.5

Combine like terms: 3.5 + -3.5 = 0.0
0.0 + 2z + z2 = 0 + -3.5
2z + z2 = 0 + -3.5

Combine like terms: 0 + -3.5 = -3.5
2z + z2 = -3.5

The z term is 2z.  Take half its coefficient (1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
2z + 1 + z2 = -3.5 + 1

Reorder the terms:
1 + 2z + z2 = -3.5 + 1

Combine like terms: -3.5 + 1 = -2.5
1 + 2z + z2 = -2.5

Factor a perfect square on the left side:
(z + 1)(z + 1) = -2.5

Can't calculate square root of the right side.

The solution to this equation could not be determined.