x^2-8x-42=

Simple and best practice solution for x^2-8x-42= 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-42= equation:


Simplifying
x2 + -8x + -42 = 0

Reorder the terms:
-42 + -8x + x2 = 0

Solving
-42 + -8x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '42' to each side of the equation.
-42 + -8x + 42 + x2 = 0 + 42

Reorder the terms:
-42 + 42 + -8x + x2 = 0 + 42

Combine like terms: -42 + 42 = 0
0 + -8x + x2 = 0 + 42
-8x + x2 = 0 + 42

Combine like terms: 0 + 42 = 42
-8x + x2 = 42

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 = 42 + 16

Reorder the terms:
16 + -8x + x2 = 42 + 16

Combine like terms: 42 + 16 = 58
16 + -8x + x2 = 58

Factor a perfect square on the left side:
(x + -4)(x + -4) = 58

Calculate the square root of the right side: 7.615773106

Break this problem into two subproblems by setting 
(x + -4) equal to 7.615773106 and -7.615773106.

Subproblem 1

x + -4 = 7.615773106 Simplifying x + -4 = 7.615773106 Reorder the terms: -4 + x = 7.615773106 Solving -4 + x = 7.615773106 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 = 7.615773106 + 4 Combine like terms: -4 + 4 = 0 0 + x = 7.615773106 + 4 x = 7.615773106 + 4 Combine like terms: 7.615773106 + 4 = 11.615773106 x = 11.615773106 Simplifying x = 11.615773106

Subproblem 2

x + -4 = -7.615773106 Simplifying x + -4 = -7.615773106 Reorder the terms: -4 + x = -7.615773106 Solving -4 + x = -7.615773106 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 = -7.615773106 + 4 Combine like terms: -4 + 4 = 0 0 + x = -7.615773106 + 4 x = -7.615773106 + 4 Combine like terms: -7.615773106 + 4 = -3.615773106 x = -3.615773106 Simplifying x = -3.615773106

Solution

The solution to the problem is based on the solutions from the subproblems. x = {11.615773106, -3.615773106}

See similar equations:

| 42x^3-55x^2+21x-2=0 | | -5(6x-2)=-30x+10 | | -8u+13=4 | | -7x=1.56 | | 0.2(z+6)=-0.2(z-0.125) | | 317.59/34 | | 2x-18+4x=180 | | 5+18x-3=4x+18-2x | | 3/2(25)-1/2+3/2((25)1/2) | | 7(1m+2)= | | 23-12i=46x-4yi | | 3(-2x-2y)=3(2) | | 3=-3y+12 | | 40x^2+57x+20= | | t^2+7t-10=0 | | -6y+13=-11 | | 13a+1=3a-4 | | -4=-4/r+8 | | -16=x/3+5 | | -2v+18=0 | | -3(z-4)-(3-7z)=2(2z+1) | | 205-x=3(3.5-x) | | 4x+5y-3x-2y= | | 8x-4=12x+6+x | | 4x+5y-3x-2y=7 | | 7x-1=52 | | P-53=14.50 | | 10=8z+5 | | 2h=8-h+17 | | X+3/5=9 | | x+5=10+2x | | 4x^2-47x+70=0 |

Equations solver categories