5a^2-12a+28=0

Solution for 5a^2-12a+28=0 equation:

Simplifying
5a2 + -12a + 28 = 0

Reorder the terms:
28 + -12a + 5a2 = 0

Solving
28 + -12a + 5a2 = 0

Solving for variable 'a'.

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

Divide each side by '5'.
5.6 + -2.4a + a2 = 0

Move the constant term to the right:

Add '-5.6' to each side of the equation.
5.6 + -2.4a + -5.6 + a2 = 0 + -5.6

Reorder the terms:
5.6 + -5.6 + -2.4a + a2 = 0 + -5.6

Combine like terms: 5.6 + -5.6 = 0.0
0.0 + -2.4a + a2 = 0 + -5.6
-2.4a + a2 = 0 + -5.6

Combine like terms: 0 + -5.6 = -5.6
-2.4a + a2 = -5.6

The a term is -2.4a.  Take half its coefficient (-1.2).
Square it (1.44) and add it to both sides.

Add '1.44' to each side of the equation.
-2.4a + 1.44 + a2 = -5.6 + 1.44

Reorder the terms:
1.44 + -2.4a + a2 = -5.6 + 1.44

Combine like terms: -5.6 + 1.44 = -4.16
1.44 + -2.4a + a2 = -4.16

Factor a perfect square on the left side:
(a + -1.2)(a + -1.2) = -4.16

Can't calculate square root of the right side.

The solution to this equation could not be determined.