x^2-20x-9=0

Simple and best practice solution for x^2-20x-9=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^2-20x-9=0 equation: 


Simplifying
x2 + -20x + -9 = 0

Reorder the terms:
-9 + -20x + x2 = 0

Solving
-9 + -20x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '9' to each side of the equation.
-9 + -20x + 9 + x2 = 0 + 9

Reorder the terms:
-9 + 9 + -20x + x2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -20x + x2 = 0 + 9
-20x + x2 = 0 + 9

Combine like terms: 0 + 9 = 9
-20x + x2 = 9

The x term is -20x.  Take half its coefficient (-10).
Square it (100) and add it to both sides.

Add '100' to each side of the equation.
-20x + 100 + x2 = 9 + 100

Reorder the terms:
100 + -20x + x2 = 9 + 100

Combine like terms: 9 + 100 = 109
100 + -20x + x2 = 109

Factor a perfect square on the left side:
(x + -10)(x + -10) = 109

Calculate the square root of the right side: 10.440306509

Break this problem into two subproblems by setting 
(x + -10) equal to 10.440306509 and -10.440306509.


Subproblem 1
x + -10 = 10.440306509

Simplifying
x + -10 = 10.440306509

Reorder the terms:
-10 + x = 10.440306509

Solving
-10 + x = 10.440306509

Solving for variable 'x'.

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

Add '10' to each side of the equation.
-10 + 10 + x = 10.440306509 + 10

Combine like terms: -10 + 10 = 0
0 + x = 10.440306509 + 10
x = 10.440306509 + 10

Combine like terms: 10.440306509 + 10 = 20.440306509
x = 20.440306509

Simplifying
x = 20.440306509


Subproblem 2
x + -10 = -10.440306509

Simplifying
x + -10 = -10.440306509

Reorder the terms:
-10 + x = -10.440306509

Solving
-10 + x = -10.440306509

Solving for variable 'x'.

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

Add '10' to each side of the equation.
-10 + 10 + x = -10.440306509 + 10

Combine like terms: -10 + 10 = 0
0 + x = -10.440306509 + 10
x = -10.440306509 + 10

Combine like terms: -10.440306509 + 10 = -0.440306509
x = -0.440306509

Simplifying
x = -0.440306509


Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {20.440306509, -0.440306509}

See similar equations:

| 1/2(y-2)+2=3/4(5y-16) | | 2n+3=33 | | x^3-36x-84=0 | | 5y+6x=-35 | | -0.1p+0.18p+6=30 | | -4+9.5(1+90)=26.5 | | 3(x+7)+8x=11x-21 | | 8p^2-16p-34=0 | | 3x+5y=144 | | 7x-5=5x+1 | | (5x-30)=180 | | 15a+5= | | -2(m-1)=15 | | 27y-29=462+16 | | 5g(g-4)+48=2g(g+3) | | C=8piefb | | x(x+2)=5x | | 12=5x+3(4-x) | | -15.5+6.5k=2.5(4.5k+5.5) | | a+8=177 | | 25=9x+1-3x | | 2x+5(x+3)=3(x+6)+5 | | 6x+4y=4050 | | 7(12.85)=54 | | 8-p=-12-8p | | x-(-5)=36 | | 6y-9-7y=-14 | | 1406.50=2.50x+4.50y | | LOG(X+2)-LOG(4X+3)=1 | | 10y=3x+2 | | -x^3+6x^2-9=0 | | 6y+5=6y-y |

Equations solver categories