0=x^2-8x-4

Simple and best practice solution for 0=x^2-8x-4 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 0=x^2-8x-4 equation:


Simplifying
0 = x2 + -8x + -4

Reorder the terms:
0 = -4 + -8x + x2

Solving
0 = -4 + -8x + x2

Solving for variable 'x'.

Combine like terms: 0 + 4 = 4
4 + 8x + -1x2 = -4 + -8x + x2 + 4 + 8x + -1x2

Reorder the terms:
4 + 8x + -1x2 = -4 + 4 + -8x + 8x + x2 + -1x2

Combine like terms: -4 + 4 = 0
4 + 8x + -1x2 = 0 + -8x + 8x + x2 + -1x2
4 + 8x + -1x2 = -8x + 8x + x2 + -1x2

Combine like terms: -8x + 8x = 0
4 + 8x + -1x2 = 0 + x2 + -1x2
4 + 8x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
4 + 8x + -1x2 = 0

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

Divide each side by '-1'.
-4 + -8x + x2 = 0

Move the constant term to the right:

Add '4' to each side of the equation.
-4 + -8x + 4 + x2 = 0 + 4

Reorder the terms:
-4 + 4 + -8x + x2 = 0 + 4

Combine like terms: -4 + 4 = 0
0 + -8x + x2 = 0 + 4
-8x + x2 = 0 + 4

Combine like terms: 0 + 4 = 4
-8x + x2 = 4

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 = 4 + 16

Reorder the terms:
16 + -8x + x2 = 4 + 16

Combine like terms: 4 + 16 = 20
16 + -8x + x2 = 20

Factor a perfect square on the left side:
(x + -4)(x + -4) = 20

Calculate the square root of the right side: 4.472135955

Break this problem into two subproblems by setting 
(x + -4) equal to 4.472135955 and -4.472135955.

Subproblem 1

x + -4 = 4.472135955 Simplifying x + -4 = 4.472135955 Reorder the terms: -4 + x = 4.472135955 Solving -4 + x = 4.472135955 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 = 4.472135955 + 4 Combine like terms: -4 + 4 = 0 0 + x = 4.472135955 + 4 x = 4.472135955 + 4 Combine like terms: 4.472135955 + 4 = 8.472135955 x = 8.472135955 Simplifying x = 8.472135955

Subproblem 2

x + -4 = -4.472135955 Simplifying x + -4 = -4.472135955 Reorder the terms: -4 + x = -4.472135955 Solving -4 + x = -4.472135955 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 = -4.472135955 + 4 Combine like terms: -4 + 4 = 0 0 + x = -4.472135955 + 4 x = -4.472135955 + 4 Combine like terms: -4.472135955 + 4 = -0.472135955 x = -0.472135955 Simplifying x = -0.472135955

Solution

The solution to the problem is based on the solutions from the subproblems. x = {8.472135955, -0.472135955}

See similar equations:

| g(7b)=7x-2 | | -3=-t^3+5t^2-2t | | 6x+17+x=-74 | | sin(5x)+cos(5x)=0 | | x*z=y*z | | 9=t^3-5t^2+2t | | 16-5(2m+8)= | | 5(3y-24)+8y=-5 | | cos(3x)+sin(2x)=0 | | 6(7x+2)=-(4-5x) | | 500-200m=25 | | 1080=180(n+2) | | 2x+118=12x-12 | | 3x-5y+6z=42 | | 14-3=-1 | | 2(3x+9)=30 | | -34=-8b-16-6b | | 4x+119=6x+137 | | 6x-19=8x-37 | | 6x-9=3x+45 | | 6w-8=2(2w+1) | | 2y-17=19 | | sin(2x)sin(x)-cos(2x)cos(x)=-cos(x) | | y/9+14=23 | | -24x^4+12x=0 | | (29-9x)=36 | | 4x-2x=-2x+36 | | x-2(3-8)=0 | | 10y+13=133 | | -13-8a-4=-3 | | (8+x)(6-x)=13 | | ac+cd=66 |

Equations solver categories