k^2-6k-9=0

Simple and best practice solution for k^2-6k-9=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 k^2-6k-9=0 equation:


Simplifying
k2 + -6k + -9 = 0

Reorder the terms:
-9 + -6k + k2 = 0

Solving
-9 + -6k + k2 = 0

Solving for variable 'k'.

Begin completing the square.

Move the constant term to the right:

Add '9' to each side of the equation.
-9 + -6k + 9 + k2 = 0 + 9

Reorder the terms:
-9 + 9 + -6k + k2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -6k + k2 = 0 + 9
-6k + k2 = 0 + 9

Combine like terms: 0 + 9 = 9
-6k + k2 = 9

The k term is -6k.  Take half its coefficient (-3).
Square it (9) and add it to both sides.

Add '9' to each side of the equation.
-6k + 9 + k2 = 9 + 9

Reorder the terms:
9 + -6k + k2 = 9 + 9

Combine like terms: 9 + 9 = 18
9 + -6k + k2 = 18

Factor a perfect square on the left side:
(k + -3)(k + -3) = 18

Calculate the square root of the right side: 4.242640687

Break this problem into two subproblems by setting 
(k + -3) equal to 4.242640687 and -4.242640687.

Subproblem 1

k + -3 = 4.242640687 Simplifying k + -3 = 4.242640687 Reorder the terms: -3 + k = 4.242640687 Solving -3 + k = 4.242640687 Solving for variable 'k'. Move all terms containing k to the left, all other terms to the right. Add '3' to each side of the equation. -3 + 3 + k = 4.242640687 + 3 Combine like terms: -3 + 3 = 0 0 + k = 4.242640687 + 3 k = 4.242640687 + 3 Combine like terms: 4.242640687 + 3 = 7.242640687 k = 7.242640687 Simplifying k = 7.242640687

Subproblem 2

k + -3 = -4.242640687 Simplifying k + -3 = -4.242640687 Reorder the terms: -3 + k = -4.242640687 Solving -3 + k = -4.242640687 Solving for variable 'k'. Move all terms containing k to the left, all other terms to the right. Add '3' to each side of the equation. -3 + 3 + k = -4.242640687 + 3 Combine like terms: -3 + 3 = 0 0 + k = -4.242640687 + 3 k = -4.242640687 + 3 Combine like terms: -4.242640687 + 3 = -1.242640687 k = -1.242640687 Simplifying k = -1.242640687

Solution

The solution to the problem is based on the solutions from the subproblems. k = {7.242640687, -1.242640687}

See similar equations:

| 144b^2-36=0 | | 7-3x=-4(2+x) | | 140+25m=400 | | 2(x-4)+3=5x | | .002x^3-.2x^2-1800=0 | | 35y-42+12y+20= | | -(k+2)=-3k-7 | | 20-9y^2=0 | | 6x=8x+30 | | 12-2(2x+10)=2 | | 36+12y=56 | | 16=6y-8 | | 3(n-5)=0 | | 8(x+6)+9=57 | | P=b+4a+cforb | | 4x-45=2x-3+x-7 | | 35x^2+10x-50= | | 9p+4=8p+8 | | 7(n+2)-3n=4+4n+10 | | 5y-9=96 | | 1x+3x= | | 6(1-3x)-2(2x-1)=18x | | 2.5n=-20 | | 9x-10y=3 | | 3s-8=9 | | 5n+3n+n+5=26 | | 5y=12x-5 | | 3x+9=56-4x | | 3a-b=1 | | a+10=27 | | 10x+1y=8 | | -5(1-5)+(-8x-2)=4x-8x |

Equations solver categories