x*x-3x-8=0

Simple and best practice solution for x*x-3x-8=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*x-3x-8=0 equation: 


Simplifying
x * x + -3x + -8 = 0

Multiply x * x
x2 + -3x + -8 = 0

Reorder the terms:
-8 + -3x + x2 = 0

Solving
-8 + -3x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '8' to each side of the equation.
-8 + -3x + 8 + x2 = 0 + 8

Reorder the terms:
-8 + 8 + -3x + x2 = 0 + 8

Combine like terms: -8 + 8 = 0
0 + -3x + x2 = 0 + 8
-3x + x2 = 0 + 8

Combine like terms: 0 + 8 = 8
-3x + x2 = 8

The x term is -3x.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3x + 2.25 + x2 = 8 + 2.25

Reorder the terms:
2.25 + -3x + x2 = 8 + 2.25

Combine like terms: 8 + 2.25 = 10.25
2.25 + -3x + x2 = 10.25

Factor a perfect square on the left side:
(x + -1.5)(x + -1.5) = 10.25

Calculate the square root of the right side: 3.201562119

Break this problem into two subproblems by setting 
(x + -1.5) equal to 3.201562119 and -3.201562119.


Subproblem 1
x + -1.5 = 3.201562119

Simplifying
x + -1.5 = 3.201562119

Reorder the terms:
-1.5 + x = 3.201562119

Solving
-1.5 + x = 3.201562119

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '1.5' to each side of the equation.
-1.5 + 1.5 + x = 3.201562119 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + x = 3.201562119 + 1.5
x = 3.201562119 + 1.5

Combine like terms: 3.201562119 + 1.5 = 4.701562119
x = 4.701562119

Simplifying
x = 4.701562119


Subproblem 2
x + -1.5 = -3.201562119

Simplifying
x + -1.5 = -3.201562119

Reorder the terms:
-1.5 + x = -3.201562119

Solving
-1.5 + x = -3.201562119

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '1.5' to each side of the equation.
-1.5 + 1.5 + x = -3.201562119 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + x = -3.201562119 + 1.5
x = -3.201562119 + 1.5

Combine like terms: -3.201562119 + 1.5 = -1.701562119
x = -1.701562119

Simplifying
x = -1.701562119


Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {4.701562119, -1.701562119}

See similar equations:

| 0.02x+0.35=1.25 | | 0.5x+8=-9 | | 0.3y+0.9=0.4-0.2y | | 12x+10y=-5 | | (2x-5+x)=38 | | -5x=-36+4x | | 2(9+x+6)=52 | | 7(x+3)=63 | | 6.4y=-2 | | 3+10x=-9+4x | | 8*-5= | | 4x^2-23x-35=0 | | 13x-2.2=2(9x+10) | | 148+36x=135x+30+510x | | ln(x+1)+ln(x-1)=1 | | 14x-2x+10=82 | | 0.21y-0.6=0.11y+1-0.7y | | -2.3q+16=-5q-38 | | 7+x+2+x=29 | | 5z-7=5+2z | | 6+2x=5-7x | | 4(3x+2)=-28 | | 6+2x=3x-17 | | x-0.7=9.15 | | 3c-9=27 | | 8x=5x^2-1 | | 8-4(4+8x)=2x-6 | | 3c^2-13c-10=0 | | 8x-(4x+6)=14 | | -8(2w-6)+(-1-5w)=0 | | 4x+96+3x=180 | | -3p+4-9p=4p-4p+1 |

Equations solver categories