a^2+3a=2

Solution for a^2+3a=2 equation:

Simplifying
a2 + 3a = 2

Reorder the terms:
3a + a2 = 2

Solving
3a + a2 = 2

Solving for variable 'a'.

Reorder the terms:
-2 + 3a + a2 = 2 + -2

Combine like terms: 2 + -2 = 0
-2 + 3a + a2 = 0

Begin completing the square.

Move the constant term to the right:

Add '2' to each side of the equation.
-2 + 3a + 2 + a2 = 0 + 2

Reorder the terms:
-2 + 2 + 3a + a2 = 0 + 2

Combine like terms: -2 + 2 = 0
0 + 3a + a2 = 0 + 2
3a + a2 = 0 + 2

Combine like terms: 0 + 2 = 2
3a + a2 = 2

The a term is 3a.  Take half its coefficient (1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
3a + 2.25 + a2 = 2 + 2.25

Reorder the terms:
2.25 + 3a + a2 = 2 + 2.25

Combine like terms: 2 + 2.25 = 4.25
2.25 + 3a + a2 = 4.25

Factor a perfect square on the left side:
(a + 1.5)(a + 1.5) = 4.25

Calculate the square root of the right side: 2.061552813

Break this problem into two subproblems by setting 
(a + 1.5) equal to 2.061552813 and -2.061552813.

Subproblem 1
a + 1.5 = 2.061552813

Simplifying
a + 1.5 = 2.061552813

Reorder the terms:
1.5 + a = 2.061552813

Solving
1.5 + a = 2.061552813

Solving for variable 'a'.

Move all terms containing a to the left, all other terms to the right.

Add '-1.5' to each side of the equation.
1.5 + -1.5 + a = 2.061552813 + -1.5

Combine like terms: 1.5 + -1.5 = 0.0
0.0 + a = 2.061552813 + -1.5
a = 2.061552813 + -1.5

Combine like terms: 2.061552813 + -1.5 = 0.561552813
a = 0.561552813

Simplifying
a = 0.561552813

Subproblem 2
a + 1.5 = -2.061552813

Simplifying
a + 1.5 = -2.061552813

Reorder the terms:
1.5 + a = -2.061552813

Solving
1.5 + a = -2.061552813

Solving for variable 'a'.

Move all terms containing a to the left, all other terms to the right.

Add '-1.5' to each side of the equation.
1.5 + -1.5 + a = -2.061552813 + -1.5

Combine like terms: 1.5 + -1.5 = 0.0
0.0 + a = -2.061552813 + -1.5
a = -2.061552813 + -1.5

Combine like terms: -2.061552813 + -1.5 = -3.561552813
a = -3.561552813

Simplifying
a = -3.561552813

Solution
The solution to the problem is based on the solutions
from the subproblems.
a = {0.561552813, -3.561552813}