x^2-8x-39=0

Simple and best practice solution for x^2-8x-39=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^2-8x-39=0 equation:


Simplifying
x2 + -8x + -39 = 0

Reorder the terms:
-39 + -8x + x2 = 0

Solving
-39 + -8x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '39' to each side of the equation.
-39 + -8x + 39 + x2 = 0 + 39

Reorder the terms:
-39 + 39 + -8x + x2 = 0 + 39

Combine like terms: -39 + 39 = 0
0 + -8x + x2 = 0 + 39
-8x + x2 = 0 + 39

Combine like terms: 0 + 39 = 39
-8x + x2 = 39

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 = 39 + 16

Reorder the terms:
16 + -8x + x2 = 39 + 16

Combine like terms: 39 + 16 = 55
16 + -8x + x2 = 55

Factor a perfect square on the left side:
(x + -4)(x + -4) = 55

Calculate the square root of the right side: 7.416198487

Break this problem into two subproblems by setting 
(x + -4) equal to 7.416198487 and -7.416198487.

Subproblem 1

x + -4 = 7.416198487 Simplifying x + -4 = 7.416198487 Reorder the terms: -4 + x = 7.416198487 Solving -4 + x = 7.416198487 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 = 7.416198487 + 4 Combine like terms: -4 + 4 = 0 0 + x = 7.416198487 + 4 x = 7.416198487 + 4 Combine like terms: 7.416198487 + 4 = 11.416198487 x = 11.416198487 Simplifying x = 11.416198487

Subproblem 2

x + -4 = -7.416198487 Simplifying x + -4 = -7.416198487 Reorder the terms: -4 + x = -7.416198487 Solving -4 + x = -7.416198487 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 = -7.416198487 + 4 Combine like terms: -4 + 4 = 0 0 + x = -7.416198487 + 4 x = -7.416198487 + 4 Combine like terms: -7.416198487 + 4 = -3.416198487 x = -3.416198487 Simplifying x = -3.416198487

Solution

The solution to the problem is based on the solutions from the subproblems. x = {11.416198487, -3.416198487}

See similar equations:

| 12/h | | 6-4d=16-d | | 12h/h | | 3(-2/3x+15)=-2x+7 | | 8y+4-5y=17 | | 3x^3-27x=o | | 100+30x=325 | | -2x+x+3=11 | | 0.7+4.5y=3.1 | | 6x^2-26x=20 | | (x^2+16)(x^2-4)=0 | | (x-6)(x+6)(x+3)(x-3)=0 | | (x^4-81)/(x^2-3x) | | -149=-4-5(-4x+1) | | 1/3(10x-2)=3 | | x^4-2x^2=24 | | x^8/x^5 | | (x-6)(x-6)(x+3)(x+3)=0 | | y=10-x^2+3x | | -2/3(a+3)=5/3a-19 | | 10+n=-2 | | y=2/3x+15 | | (x^2)(x-6)(x-3)=0 | | 0.3x+1.2y=2.4 | | 7x+3x-2=17 | | x^2-2x-12=1 | | 6+z= | | 3(2/3+15)=-2x+7 | | k/-3=11 | | (7x-6)(2x+9)= | | -5/26+a=-7/13 | | 9k^2+24k-48=0 |

Equations solver categories