121-9x-x^2=0

Simple and best practice solution for 121-9x-x^2=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 121-9x-x^2=0 equation:


Simplifying
121 + -9x + -1x2 = 0

Solving
121 + -9x + -1x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-121 + 9x + x2 = 0

Move the constant term to the right:

Add '121' to each side of the equation.
-121 + 9x + 121 + x2 = 0 + 121

Reorder the terms:
-121 + 121 + 9x + x2 = 0 + 121

Combine like terms: -121 + 121 = 0
0 + 9x + x2 = 0 + 121
9x + x2 = 0 + 121

Combine like terms: 0 + 121 = 121
9x + x2 = 121

The x term is 9x.  Take half its coefficient (4.5).
Square it (20.25) and add it to both sides.

Add '20.25' to each side of the equation.
9x + 20.25 + x2 = 121 + 20.25

Reorder the terms:
20.25 + 9x + x2 = 121 + 20.25

Combine like terms: 121 + 20.25 = 141.25
20.25 + 9x + x2 = 141.25

Factor a perfect square on the left side:
(x + 4.5)(x + 4.5) = 141.25

Calculate the square root of the right side: 11.884864324

Break this problem into two subproblems by setting 
(x + 4.5) equal to 11.884864324 and -11.884864324.

Subproblem 1

x + 4.5 = 11.884864324 Simplifying x + 4.5 = 11.884864324 Reorder the terms: 4.5 + x = 11.884864324 Solving 4.5 + x = 11.884864324 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-4.5' to each side of the equation. 4.5 + -4.5 + x = 11.884864324 + -4.5 Combine like terms: 4.5 + -4.5 = 0.0 0.0 + x = 11.884864324 + -4.5 x = 11.884864324 + -4.5 Combine like terms: 11.884864324 + -4.5 = 7.384864324 x = 7.384864324 Simplifying x = 7.384864324

Subproblem 2

x + 4.5 = -11.884864324 Simplifying x + 4.5 = -11.884864324 Reorder the terms: 4.5 + x = -11.884864324 Solving 4.5 + x = -11.884864324 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-4.5' to each side of the equation. 4.5 + -4.5 + x = -11.884864324 + -4.5 Combine like terms: 4.5 + -4.5 = 0.0 0.0 + x = -11.884864324 + -4.5 x = -11.884864324 + -4.5 Combine like terms: -11.884864324 + -4.5 = -16.384864324 x = -16.384864324 Simplifying x = -16.384864324

Solution

The solution to the problem is based on the solutions from the subproblems. x = {7.384864324, -16.384864324}

See similar equations:

| 7+11=19 | | 2(8x-2)-x(5x+7)=6-x(3x+1) | | x+40+3x-17=2x-5 | | 2(4x-5)=ax+b | | 6(2x+9)=6 | | 5+.50n=25 | | 2x-5+x+40=3x-17 | | 2x-5+3x-17=x+40 | | 13-5m=-3m+1 | | 5+25t-16t^2=4 | | 9n-2=61 | | 3-10x-5-2x+8=0 | | -7(4x+6x)=266 | | Y-2=m(x-2) | | y=0.625(-37)-37 | | (x+5)(x-1)=280 | | 5x^2+4x=17 | | 12-cx+32=10 | | y=0.625*0.625-37 | | 28=-7x-6(-2x+2) | | N+18=26 | | -1+4x=2+5x | | 7(a-1)=3(a+1) | | n-21=49 | | 13k=-4 | | 984-16t^2=0 | | 7(a-4)=3(a+1) | | y=-6x-24 | | 2c-10+3c+4=14 | | 2x-18y=18 | | 64=x(12+x) | | x^2-x+9=5-1 |

Equations solver categories