-x^2-8x-9=0

Simple and best practice solution for -x^2-8x-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^2-8x-9=0 equation: 


Simplifying
-1x2 + -8x + -9 = 0

Reorder the terms:
-9 + -8x + -1x2 = 0

Solving
-9 + -8x + -1x2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '-1'.
-1(9 + 8x + x2) = 0

Ignore the factor -1.

Subproblem 1
Set the factor '(9 + 8x + x2)' equal to zero and attempt to solve:

Simplifying
9 + 8x + x2 = 0

Solving
9 + 8x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-9' to each side of the equation.
9 + 8x + -9 + x2 = 0 + -9

Reorder the terms:
9 + -9 + 8x + x2 = 0 + -9

Combine like terms: 9 + -9 = 0
0 + 8x + x2 = 0 + -9
8x + x2 = 0 + -9

Combine like terms: 0 + -9 = -9
8x + x2 = -9

The x term is 8x.  Take half its coefficient (4).
Square it (16) and add it to both sides.

Add '16' to each side of the equation.
8x + 16 + x2 = -9 + 16

Reorder the terms:
16 + 8x + x2 = -9 + 16

Combine like terms: -9 + 16 = 7
16 + 8x + x2 = 7

Factor a perfect square on the left side:
(x + 4)(x + 4) = 7

Calculate the square root of the right side: 2.645751311

Break this problem into two subproblems by setting 
(x + 4) equal to 2.645751311 and -2.645751311.


Subproblem 1
x + 4 = 2.645751311

Simplifying
x + 4 = 2.645751311

Reorder the terms:
4 + x = 2.645751311

Solving
4 + x = 2.645751311

Solving for variable 'x'.

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

Add '-4' to each side of the equation.
4 + -4 + x = 2.645751311 + -4

Combine like terms: 4 + -4 = 0
0 + x = 2.645751311 + -4
x = 2.645751311 + -4

Combine like terms: 2.645751311 + -4 = -1.354248689
x = -1.354248689

Simplifying
x = -1.354248689


Subproblem 2
x + 4 = -2.645751311

Simplifying
x + 4 = -2.645751311

Reorder the terms:
4 + x = -2.645751311

Solving
4 + x = -2.645751311

Solving for variable 'x'.

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

Add '-4' to each side of the equation.
4 + -4 + x = -2.645751311 + -4

Combine like terms: 4 + -4 = 0
0 + x = -2.645751311 + -4
x = -2.645751311 + -4

Combine like terms: -2.645751311 + -4 = -6.645751311
x = -6.645751311

Simplifying
x = -6.645751311


Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {-1.354248689, -6.645751311}
Solution
x = {-1.354248689, -6.645751311}

See similar equations:

| e*80=2 | | 5=2x | | m*7=13 | | 16=w*4 | | c*9=6 | | -7-4r=-3(-7-8r) | | 7(x+2)=8-5(x-7) | | 8l+8-l=9-8 | | 3x-2x+10=10+5x-40 | | 4x+2=8-2x | | C^3-216=y | | 3(-7-6x)-8=37+4x | | 5+2x=7(x+2)-6(x-2) | | x^2+21x+59=0 | | -(3-m)=-(4m+3) | | 100/566=1/9 | | -(x+1)+2=2x+1-3x | | 3(x+2)=9x+3-6x+3 | | 900/566= | | 10x-9=21+2x+3x | | -7a-(-2b)= | | k*36=8 | | -2(t-5)+9t=3t-4 | | 4(x-2)=8x-6-4x | | 4x^2-64x-69=0 | | 9z+3-5z=7+3z+4 | | 5xb=20 | | -1(-10)= | | 3.2q-1.8-5.4q=-3.2q-2.4 | | 15x-7=45x+11 | | 18-5m=3m-2m | | -6a^2-5a+21=0 |

Equations solver categories