u^2-u-9=0

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


Simplifying
u2 + -1u + -9 = 0

Reorder the terms:
-9 + -1u + u2 = 0

Solving
-9 + -1u + u2 = 0

Solving for variable 'u'.

Begin completing the square.

Move the constant term to the right:

Add '9' to each side of the equation.
-9 + -1u + 9 + u2 = 0 + 9

Reorder the terms:
-9 + 9 + -1u + u2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -1u + u2 = 0 + 9
-1u + u2 = 0 + 9

Combine like terms: 0 + 9 = 9
-1u + u2 = 9

The u term is -1u.  Take half its coefficient (-0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-1u + 0.25 + u2 = 9 + 0.25

Reorder the terms:
0.25 + -1u + u2 = 9 + 0.25

Combine like terms: 9 + 0.25 = 9.25
0.25 + -1u + u2 = 9.25

Factor a perfect square on the left side:
(u + -0.5)(u + -0.5) = 9.25

Calculate the square root of the right side: 3.041381265

Break this problem into two subproblems by setting 
(u + -0.5) equal to 3.041381265 and -3.041381265.

Subproblem 1

u + -0.5 = 3.041381265 Simplifying u + -0.5 = 3.041381265 Reorder the terms: -0.5 + u = 3.041381265 Solving -0.5 + u = 3.041381265 Solving for variable 'u'. Move all terms containing u to the left, all other terms to the right. Add '0.5' to each side of the equation. -0.5 + 0.5 + u = 3.041381265 + 0.5 Combine like terms: -0.5 + 0.5 = 0.0 0.0 + u = 3.041381265 + 0.5 u = 3.041381265 + 0.5 Combine like terms: 3.041381265 + 0.5 = 3.541381265 u = 3.541381265 Simplifying u = 3.541381265

Subproblem 2

u + -0.5 = -3.041381265 Simplifying u + -0.5 = -3.041381265 Reorder the terms: -0.5 + u = -3.041381265 Solving -0.5 + u = -3.041381265 Solving for variable 'u'. Move all terms containing u to the left, all other terms to the right. Add '0.5' to each side of the equation. -0.5 + 0.5 + u = -3.041381265 + 0.5 Combine like terms: -0.5 + 0.5 = 0.0 0.0 + u = -3.041381265 + 0.5 u = -3.041381265 + 0.5 Combine like terms: -3.041381265 + 0.5 = -2.541381265 u = -2.541381265 Simplifying u = -2.541381265

Solution

The solution to the problem is based on the solutions from the subproblems. u = {3.541381265, -2.541381265}

See similar equations:

| 3c-4/3-2c+4/6=5c-1/9 | | 6(2x+11)=126 | | 4xy-3z+2=0 | | 123-2x=16x+21 | | -6e-7+3e=2-4e+5 | | 4x+33=25 | | 5(10x+8)=190 | | 2/5x4/7 | | 13=x/3-5 | | x^2+11x=-12x | | 12b-5=8b-33 | | 5-2x=x+3 | | 21000=3400t+600 | | -8=(3)/(x+5) | | X^2+3x-3=3 | | 2(4x-5)=8x-10 | | 4i-5=2i-6+i | | 3x+50=32 | | 2+(2x+9)=6 | | 5(13-m)-10m=0 | | X/7+5=9 | | 4/5(5y-15)=-8 | | 4z-10+6z=-30 | | 5t=1/2 | | 3fg+7f+2fg= | | -5=7-x | | 5/12(1296)-15 | | 9a^2-24ap+16p^2= | | (x+7)(7x-1)=43x+5x^2 | | 1/3(6x+3)-4(3x-2) | | 1/p-1/m-1/n=6 | | -18(-5+m)=666 |

Equations solver categories