2x^2+2x-399=0

Simple and best practice solution for 2x^2+2x-399=0 equation. Check how easy it is, and learn it for the future. Our solution is simple, and easy to understand, so don`t hesitate to use it as a solution of your homework.

If it's not what You are looking for type in the equation solver your own equation and let us solve it.

Solution for 2x^2+2x-399=0 equation:


Simplifying
2x2 + 2x + -399 = 0

Reorder the terms:
-399 + 2x + 2x2 = 0

Solving
-399 + 2x + 2x2 = 0

Solving for variable 'x'.

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

Divide each side by '2'.
-199.5 + x + x2 = 0

Move the constant term to the right:

Add '199.5' to each side of the equation.
-199.5 + x + 199.5 + x2 = 0 + 199.5

Reorder the terms:
-199.5 + 199.5 + x + x2 = 0 + 199.5

Combine like terms: -199.5 + 199.5 = 0.0
0.0 + x + x2 = 0 + 199.5
x + x2 = 0 + 199.5

Combine like terms: 0 + 199.5 = 199.5
x + x2 = 199.5

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
 + 0.25 + x2 = 199.5 + 0.25

Combine like terms:  + 0.25 = 1.25
1.25 + x2 = 199.5 + 0.25

Combine like terms: 199.5 + 0.25 = 199.75
1.25 + x2 = 199.75

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = 199.75

Calculate the square root of the right side: 14.133294025

Break this problem into two subproblems by setting 
(x + 0.5) equal to 14.133294025 and -14.133294025.

Subproblem 1

x + 0.5 = 14.133294025 Simplifying x + 0.5 = 14.133294025 Reorder the terms: 0.5 + x = 14.133294025 Solving 0.5 + x = 14.133294025 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = 14.133294025 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = 14.133294025 + -0.5 x = 14.133294025 + -0.5 Combine like terms: 14.133294025 + -0.5 = 13.633294025 x = 13.633294025 Simplifying x = 13.633294025

Subproblem 2

x + 0.5 = -14.133294025 Simplifying x + 0.5 = -14.133294025 Reorder the terms: 0.5 + x = -14.133294025 Solving 0.5 + x = -14.133294025 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = -14.133294025 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = -14.133294025 + -0.5 x = -14.133294025 + -0.5 Combine like terms: -14.133294025 + -0.5 = -14.633294025 x = -14.633294025 Simplifying x = -14.633294025

Solution

The solution to the problem is based on the solutions from the subproblems. x = {13.633294025, -14.633294025}

See similar equations:

| 7k^2+9k= | | b^2+10b+20= | | 9x^2+25x-6= | | 7x^2-31x-20= | | 1.5x-8=3x+4 | | -95x^2-20x-16=0 | | -4x+2=-x+23 | | n^2*n^7= | | -5(0)+y=-3 | | 2x-3=5x+18 | | [6x+5][6x-5]= | | 24= | | (-2)(-2)= | | 5x-4-4x-8=26 | | x-214=551 | | x+341=547 | | xx+2x+17=50 | | x+2x+17=50 | | 2x+17=50 | | 7y=21x-28 | | -3(t-5)-(t+2)=7 | | -3r+54=2r+3 | | 6x+-3=9x | | 6x-3=9x | | 7p-tp=tp-7 | | z+14.5=5.4 | | 9x^2+7x-56= | | 12+5(4*11)+(5+2)= | | 9x^2y+73xy+70x= | | 2334x-4234=324 | | 30y-28y=-24+24 | | 4x^3+5x+3x=0 |

Equations solver categories