-x^4+81x^2+9=0

Simple and best practice solution for -x^4+81x^2+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^4+81x^2+9=0 equation: 


Simplifying
-1x4 + 81x2 + 9 = 0

Reorder the terms:
9 + 81x2 + -1x4 = 0

Solving
9 + 81x2 + -1x4 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-9 + -81x2 + x4 = 0

Move the constant term to the right:

Add '9' to each side of the equation.
-9 + -81x2 + 9 + x4 = 0 + 9

Reorder the terms:
-9 + 9 + -81x2 + x4 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -81x2 + x4 = 0 + 9
-81x2 + x4 = 0 + 9

Combine like terms: 0 + 9 = 9
-81x2 + x4 = 9

The x term is -81x2.  Take half its coefficient (-40.5).
Square it (1640.25) and add it to both sides.

Add '1640.25' to each side of the equation.
-81x2 + 1640.25 + x4 = 9 + 1640.25

Reorder the terms:
1640.25 + -81x2 + x4 = 9 + 1640.25

Combine like terms: 9 + 1640.25 = 1649.25
1640.25 + -81x2 + x4 = 1649.25

Factor a perfect square on the left side:
(x2 + -40.5)(x2 + -40.5) = 1649.25

Calculate the square root of the right side: 40.610959112

Break this problem into two subproblems by setting 
(x2 + -40.5) equal to 40.610959112 and -40.610959112.


Subproblem 1
x2 + -40.5 = 40.610959112

Simplifying
x2 + -40.5 = 40.610959112

Reorder the terms:
-40.5 + x2 = 40.610959112

Solving
-40.5 + x2 = 40.610959112

Solving for variable 'x'.

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

Add '40.5' to each side of the equation.
-40.5 + 40.5 + x2 = 40.610959112 + 40.5

Combine like terms: -40.5 + 40.5 = 0.0
0.0 + x2 = 40.610959112 + 40.5
x2 = 40.610959112 + 40.5

Combine like terms: 40.610959112 + 40.5 = 81.110959112
x2 = 81.110959112

Simplifying
x2 = 81.110959112

Take the square root of each side:
x = {-9.006162285, 9.006162285}


Subproblem 2
x2 + -40.5 = -40.610959112

Simplifying
x2 + -40.5 = -40.610959112

Reorder the terms:
-40.5 + x2 = -40.610959112

Solving
-40.5 + x2 = -40.610959112

Solving for variable 'x'.

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

Add '40.5' to each side of the equation.
-40.5 + 40.5 + x2 = -40.610959112 + 40.5

Combine like terms: -40.5 + 40.5 = 0.0
0.0 + x2 = -40.610959112 + 40.5
x2 = -40.610959112 + 40.5

Combine like terms: -40.610959112 + 40.5 = -0.110959112
x2 = -0.110959112

Simplifying
x2 = -0.110959112

Reorder the terms:
0.110959112 + x2 = -0.110959112 + 0.110959112

Combine like terms: -0.110959112 + 0.110959112 = 0.000000000
0.110959112 + x2 = 0.000000000

The solution to this equation could not be determined.This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.

See similar equations:

| c-8=44 | | 7+(h+3)=6(h-3) | | 9/7=3u | | y-4=2/3(x-9) | | (2-v)(5v-3)=0 | | 3=2(v+-4)+1 | | 4y-1=-12 | | 7(x+10)= | | 2x+5(x-6)=3x+14 | | 4/0.5x-2.5/=0 | | 258/100 | | 4x-1=8x-19 | | -10+24.0=14 | | ((-4.8)/(1.1-2.6))/0.4 | | -1.4+-10=14 | | -10-4.0=14 | | 2w-7w=-45 | | 2u=4u-18 | | -7(4-9n)= | | -10+4=14 | | 1/4x-3=5-2y | | 1/2x1/2x1/2= | | 8t=t+49 | | -10+u=14 | | 4a+3a=24 | | 292.85/100 | | 36.5/100 | | 11x-3=53 | | 2x+48+2x=2x+18 | | -2-x=-3 | | 9(20)=5F-160 | | X+x+4000+x+6000=44000 |

Equations solver categories