x^2-x-4=0

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


Simplifying
x2 + -1x + -4 = 0

Reorder the terms:
-4 + -1x + x2 = 0

Solving
-4 + -1x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '4' to each side of the equation.
-4 + -1x + 4 + x2 = 0 + 4

Reorder the terms:
-4 + 4 + -1x + x2 = 0 + 4

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

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

The x term is -1x.  Take half its coefficient (-0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-1x + 0.25 + x2 = 4 + 0.25

Reorder the terms:
0.25 + -1x + x2 = 4 + 0.25

Combine like terms: 4 + 0.25 = 4.25
0.25 + -1x + x2 = 4.25

Factor a perfect square on the left side:
(x + -0.5)(x + -0.5) = 4.25

Calculate the square root of the right side: 2.061552813

Break this problem into two subproblems by setting 
(x + -0.5) equal to 2.061552813 and -2.061552813.

Subproblem 1

x + -0.5 = 2.061552813 Simplifying x + -0.5 = 2.061552813 Reorder the terms: -0.5 + x = 2.061552813 Solving -0.5 + x = 2.061552813 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.5' to each side of the equation. -0.5 + 0.5 + x = 2.061552813 + 0.5 Combine like terms: -0.5 + 0.5 = 0.0 0.0 + x = 2.061552813 + 0.5 x = 2.061552813 + 0.5 Combine like terms: 2.061552813 + 0.5 = 2.561552813 x = 2.561552813 Simplifying x = 2.561552813

Subproblem 2

x + -0.5 = -2.061552813 Simplifying x + -0.5 = -2.061552813 Reorder the terms: -0.5 + x = -2.061552813 Solving -0.5 + x = -2.061552813 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.5' to each side of the equation. -0.5 + 0.5 + x = -2.061552813 + 0.5 Combine like terms: -0.5 + 0.5 = 0.0 0.0 + x = -2.061552813 + 0.5 x = -2.061552813 + 0.5 Combine like terms: -2.061552813 + 0.5 = -1.561552813 x = -1.561552813 Simplifying x = -1.561552813

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.561552813, -1.561552813}

See similar equations:

| 174-5x=6x+20 | | 1-5x=10-8x | | 6x+12=111-5x | | 9x-11=7x+3 | | x^2-3x-5=0 | | 2x+37=11x-44 | | x^2+3x-5=0 | | x^2-7x+5=0 | | 6y=4y^2+2 | | m^2+2m-3=0 | | 4(-2-7x)=216 | | 4(1x+3)=24 | | -2(1x-6)=-2 | | 13(-6.3)= | | 2(8-n)=2 | | 0.3x^2+0.1x+4.2=8 | | 0.3t^2+0.1T+4.2=8 | | 4t+7t+6t=-33 | | 5x+(2x*5)+(3x*15)=180 | | x-3(2x+4)=7x | | 10+2y=12y | | 3x^2+4x-4=0 | | x+2y=30 | | -26y=-130 | | (5x)6=5 | | 2(x+y)+.05=x(.01)+y(100) | | 2(x)+.05=y | | 5x-3x=4x-2 | | x+5x+69858+9986x=64858x+992 | | 180=5x+15 | | x+4y=3 | | (6x^3+8x^2-15x-13)=(2x^2-5) |

Equations solver categories