x^2-x-20=20

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


Simplifying
x2 + -1x + -20 = 20

Reorder the terms:
-20 + -1x + x2 = 20

Solving
-20 + -1x + x2 = 20

Solving for variable 'x'.

Reorder the terms:
-20 + -20 + -1x + x2 = 20 + -20

Combine like terms: -20 + -20 = -40
-40 + -1x + x2 = 20 + -20

Combine like terms: 20 + -20 = 0
-40 + -1x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '40' to each side of the equation.
-40 + -1x + 40 + x2 = 0 + 40

Reorder the terms:
-40 + 40 + -1x + x2 = 0 + 40

Combine like terms: -40 + 40 = 0
0 + -1x + x2 = 0 + 40
-1x + x2 = 0 + 40

Combine like terms: 0 + 40 = 40
-1x + x2 = 40

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 = 40 + 0.25

Reorder the terms:
0.25 + -1x + x2 = 40 + 0.25

Combine like terms: 40 + 0.25 = 40.25
0.25 + -1x + x2 = 40.25

Factor a perfect square on the left side:
(x + -0.5)(x + -0.5) = 40.25

Calculate the square root of the right side: 6.34428877

Break this problem into two subproblems by setting 
(x + -0.5) equal to 6.34428877 and -6.34428877.

Subproblem 1

x + -0.5 = 6.34428877 Simplifying x + -0.5 = 6.34428877 Reorder the terms: -0.5 + x = 6.34428877 Solving -0.5 + x = 6.34428877 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 = 6.34428877 + 0.5 Combine like terms: -0.5 + 0.5 = 0.0 0.0 + x = 6.34428877 + 0.5 x = 6.34428877 + 0.5 Combine like terms: 6.34428877 + 0.5 = 6.84428877 x = 6.84428877 Simplifying x = 6.84428877

Subproblem 2

x + -0.5 = -6.34428877 Simplifying x + -0.5 = -6.34428877 Reorder the terms: -0.5 + x = -6.34428877 Solving -0.5 + x = -6.34428877 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 = -6.34428877 + 0.5 Combine like terms: -0.5 + 0.5 = 0.0 0.0 + x = -6.34428877 + 0.5 x = -6.34428877 + 0.5 Combine like terms: -6.34428877 + 0.5 = -5.84428877 x = -5.84428877 Simplifying x = -5.84428877

Solution

The solution to the problem is based on the solutions from the subproblems. x = {6.84428877, -5.84428877}

See similar equations:

| -9+5y+4-3y= | | 7(w-1)-9=-2(-6w+1)-w | | 37-93d-95-3d+7+6d= | | -2(w+1)=4w-4+3(4w+2) | | 5u^3/40u^7 | | -2y-(5y+1)= | | 2x+4(x+6)=2(x+28) | | 2(u+3)=-2(4u-8)+2u | | 4x^5/40x^2 | | 3x+x=592 | | 880=x+(x+800) | | 2m+5n+9m+7n= | | 4/-8 | | -3(-6y+9)-y=5(y-6)-3 | | 300=4x | | 9991=2.55Y+2.30X | | 38-82d-89-2d+6+5d= | | 2x+y-2z-2x= | | -8x-2x= | | X+x+4547=210355 | | 4.2*2+2.5y=-9.1 | | y=15cos(4x) | | 4.2*1+2.5y=-9.1 | | (5x+6)(5x-1)= | | 15+15y=9x | | -2(3v-6)+8v=7+3(2v-3) | | 10x-9(x-2)=24 | | 4(2x+8)=5(2x+11) | | 2y+2z+z+x= | | 4.5x^2+72=0 | | 7n+15-3n+4=21 | | (3ln(5x))=6 |

Equations solver categories