2x^2+42x+115=0

Simple and best practice solution for 2x^2+42x+115=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+42x+115=0 equation:


Simplifying
2x2 + 42x + 115 = 0

Reorder the terms:
115 + 42x + 2x2 = 0

Solving
115 + 42x + 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'.
57.5 + 21x + x2 = 0

Move the constant term to the right:

Add '-57.5' to each side of the equation.
57.5 + 21x + -57.5 + x2 = 0 + -57.5

Reorder the terms:
57.5 + -57.5 + 21x + x2 = 0 + -57.5

Combine like terms: 57.5 + -57.5 = 0.0
0.0 + 21x + x2 = 0 + -57.5
21x + x2 = 0 + -57.5

Combine like terms: 0 + -57.5 = -57.5
21x + x2 = -57.5

The x term is 21x.  Take half its coefficient (10.5).
Square it (110.25) and add it to both sides.

Add '110.25' to each side of the equation.
21x + 110.25 + x2 = -57.5 + 110.25

Reorder the terms:
110.25 + 21x + x2 = -57.5 + 110.25

Combine like terms: -57.5 + 110.25 = 52.75
110.25 + 21x + x2 = 52.75

Factor a perfect square on the left side:
(x + 10.5)(x + 10.5) = 52.75

Calculate the square root of the right side: 7.262919523

Break this problem into two subproblems by setting 
(x + 10.5) equal to 7.262919523 and -7.262919523.

Subproblem 1

x + 10.5 = 7.262919523 Simplifying x + 10.5 = 7.262919523 Reorder the terms: 10.5 + x = 7.262919523 Solving 10.5 + x = 7.262919523 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-10.5' to each side of the equation. 10.5 + -10.5 + x = 7.262919523 + -10.5 Combine like terms: 10.5 + -10.5 = 0.0 0.0 + x = 7.262919523 + -10.5 x = 7.262919523 + -10.5 Combine like terms: 7.262919523 + -10.5 = -3.237080477 x = -3.237080477 Simplifying x = -3.237080477

Subproblem 2

x + 10.5 = -7.262919523 Simplifying x + 10.5 = -7.262919523 Reorder the terms: 10.5 + x = -7.262919523 Solving 10.5 + x = -7.262919523 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-10.5' to each side of the equation. 10.5 + -10.5 + x = -7.262919523 + -10.5 Combine like terms: 10.5 + -10.5 = 0.0 0.0 + x = -7.262919523 + -10.5 x = -7.262919523 + -10.5 Combine like terms: -7.262919523 + -10.5 = -17.762919523 x = -17.762919523 Simplifying x = -17.762919523

Solution

The solution to the problem is based on the solutions from the subproblems. x = {-3.237080477, -17.762919523}

See similar equations:

| -5=x-(-6) | | 5-3m=125 | | 5f+4f-3f-12f=9 | | 2(3x+5)+4=6x+14 | | 7x+6x=67 | | 6x(x-1)=x+7 | | 0.2(7+2)=0.4+1.4 | | 5-10c+8c=45-30 | | 4n+6=410 | | 4x-3(2x-7)=x+6 | | k-6=-20 | | 14lbs=km | | 11y=6 | | -3a-8+2a=13 | | 2(x+8)+5(x-1)=60 | | -9x+3=-4x-2 | | 0.0546hl=ml | | R+15=12 | | y=19x^2-70x+320 | | 14+x=34 | | 3.25n+0.75=y | | 50x^3-50=0 | | 6x-9=-75 | | (-10)+(-10)=0 | | 2n-4+4n=2 | | -5x-7=x+5 | | 15x-7.5=39 | | 5n^2-31n=0 | | 11=7(x+1)-2(3-8x)-3x | | 53-2x=18-3x | | 673.2cm=dg | | -3x+2x-6x= |

Equations solver categories