x^2+21x+2=0

Simple and best practice solution for x^2+21x+2=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 x^2+21x+2=0 equation:


Simplifying
x2 + 21x + 2 = 0

Reorder the terms:
2 + 21x + x2 = 0

Solving
2 + 21x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-2' to each side of the equation.
2 + 21x + -2 + x2 = 0 + -2

Reorder the terms:
2 + -2 + 21x + x2 = 0 + -2

Combine like terms: 2 + -2 = 0
0 + 21x + x2 = 0 + -2
21x + x2 = 0 + -2

Combine like terms: 0 + -2 = -2
21x + x2 = -2

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 = -2 + 110.25

Reorder the terms:
110.25 + 21x + x2 = -2 + 110.25

Combine like terms: -2 + 110.25 = 108.25
110.25 + 21x + x2 = 108.25

Factor a perfect square on the left side:
(x + 10.5)(x + 10.5) = 108.25

Calculate the square root of the right side: 10.404326023

Break this problem into two subproblems by setting 
(x + 10.5) equal to 10.404326023 and -10.404326023.

Subproblem 1

x + 10.5 = 10.404326023 Simplifying x + 10.5 = 10.404326023 Reorder the terms: 10.5 + x = 10.404326023 Solving 10.5 + x = 10.404326023 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 = 10.404326023 + -10.5 Combine like terms: 10.5 + -10.5 = 0.0 0.0 + x = 10.404326023 + -10.5 x = 10.404326023 + -10.5 Combine like terms: 10.404326023 + -10.5 = -0.095673977 x = -0.095673977 Simplifying x = -0.095673977

Subproblem 2

x + 10.5 = -10.404326023 Simplifying x + 10.5 = -10.404326023 Reorder the terms: 10.5 + x = -10.404326023 Solving 10.5 + x = -10.404326023 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 = -10.404326023 + -10.5 Combine like terms: 10.5 + -10.5 = 0.0 0.0 + x = -10.404326023 + -10.5 x = -10.404326023 + -10.5 Combine like terms: -10.404326023 + -10.5 = -20.904326023 x = -20.904326023 Simplifying x = -20.904326023

Solution

The solution to the problem is based on the solutions from the subproblems. x = {-0.095673977, -20.904326023}

See similar equations:

| 8y-2=3y+28 | | 13x-4x=18 | | 3w-9=18 | | X^2-11X+45=0 | | 5(8x-2y)-5(2x+5y)= | | 5(x)=-1 | | x/2.2-20.4 | | -5(x)=-.5(x)-1 | | -3.4x+2.3=-14.7 | | (lnx)/0.5 | | 4x^4-40x^2=-36 | | x^2-9x-14= | | P^216p-22=0 | | -4c-2y=-12 | | x^3-11.5x^2-73=0 | | 2(11w+5)= | | (-16x)(x-50)=0 | | 7x-40=7x | | 125,000-7%= | | -65*9=2x | | 50-2x=8-8x | | -5(2t-4)+7t=8t-5 | | log(4).5=x | | 4x+1=75 | | 125,000+7%= | | X+3y=-7(x-6) | | (5z+8)(7-z)=0 | | 3x=15-3 | | 5*2=-13x | | 7*10=9x | | 5(2-z)/4 | | 7+11x=-33+x |

Equations solver categories