3=x^2-2x-8

Simple and best practice solution for 3=x^2-2x-8 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 3=x^2-2x-8 equation:


Simplifying
3 = x2 + -2x + -8

Reorder the terms:
3 = -8 + -2x + x2

Solving
3 = -8 + -2x + x2

Solving for variable 'x'.

Combine like terms: 3 + 8 = 11
11 + 2x + -1x2 = -8 + -2x + x2 + 8 + 2x + -1x2

Reorder the terms:
11 + 2x + -1x2 = -8 + 8 + -2x + 2x + x2 + -1x2

Combine like terms: -8 + 8 = 0
11 + 2x + -1x2 = 0 + -2x + 2x + x2 + -1x2
11 + 2x + -1x2 = -2x + 2x + x2 + -1x2

Combine like terms: -2x + 2x = 0
11 + 2x + -1x2 = 0 + x2 + -1x2
11 + 2x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
11 + 2x + -1x2 = 0

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

Divide each side by '-1'.
-11 + -2x + x2 = 0

Move the constant term to the right:

Add '11' to each side of the equation.
-11 + -2x + 11 + x2 = 0 + 11

Reorder the terms:
-11 + 11 + -2x + x2 = 0 + 11

Combine like terms: -11 + 11 = 0
0 + -2x + x2 = 0 + 11
-2x + x2 = 0 + 11

Combine like terms: 0 + 11 = 11
-2x + x2 = 11

The x term is -2x.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2x + 1 + x2 = 11 + 1

Reorder the terms:
1 + -2x + x2 = 11 + 1

Combine like terms: 11 + 1 = 12
1 + -2x + x2 = 12

Factor a perfect square on the left side:
(x + -1)(x + -1) = 12

Calculate the square root of the right side: 3.464101615

Break this problem into two subproblems by setting 
(x + -1) equal to 3.464101615 and -3.464101615.

Subproblem 1

x + -1 = 3.464101615 Simplifying x + -1 = 3.464101615 Reorder the terms: -1 + x = 3.464101615 Solving -1 + x = 3.464101615 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + x = 3.464101615 + 1 Combine like terms: -1 + 1 = 0 0 + x = 3.464101615 + 1 x = 3.464101615 + 1 Combine like terms: 3.464101615 + 1 = 4.464101615 x = 4.464101615 Simplifying x = 4.464101615

Subproblem 2

x + -1 = -3.464101615 Simplifying x + -1 = -3.464101615 Reorder the terms: -1 + x = -3.464101615 Solving -1 + x = -3.464101615 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + x = -3.464101615 + 1 Combine like terms: -1 + 1 = 0 0 + x = -3.464101615 + 1 x = -3.464101615 + 1 Combine like terms: -3.464101615 + 1 = -2.464101615 x = -2.464101615 Simplifying x = -2.464101615

Solution

The solution to the problem is based on the solutions from the subproblems. x = {4.464101615, -2.464101615}

See similar equations:

| 4(6x-8x)=3(10+30) | | -2x+8+7x=4x-8 | | 200=-16t^2+128t | | 7ln(x+8)-5ln(x)= | | -4+2x+x=5 | | -113+10x+4x=195 | | 2-5=17 | | 4(6x-8x)=2(20+20) | | -56x^2+800x+30000=0 | | -10+12x-11x=16 | | 7m+17-5m=31 | | x=-56x^2+800x+30000 | | 6ln(7x)=30 | | 2x^2+4y^2-3xy+2=0 | | 180=x+(x-2)+72 | | (6v^2-v-4)+(2v^2-5v+3)= | | 2+m(-1)-7m+3=0 | | 4n^2-4n-35= | | x+2+12x-1=20+x+5 | | (3x+22)+(3x+128)=180 | | -x+3x-16=30 | | F(x-1)=x^2+kx-17 | | y=15x-215 | | -4x+3=-7+6x | | -128-12x-3x=127 | | 14x^2+86x+12=0 | | 128-12x-3x=127 | | 2z+4=16-12 | | 8x+8=x^2-5 | | x^8-5x^7-3x^6= | | 3x+18-4x=20 | | -2=18-4x |

Equations solver categories