x^2+18x-99=0

Simple and best practice solution for x^2+18x-99=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^2+18x-99=0 equation:


Simplifying
x2 + 18x + -99 = 0

Reorder the terms:
-99 + 18x + x2 = 0

Solving
-99 + 18x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '99' to each side of the equation.
-99 + 18x + 99 + x2 = 0 + 99

Reorder the terms:
-99 + 99 + 18x + x2 = 0 + 99

Combine like terms: -99 + 99 = 0
0 + 18x + x2 = 0 + 99
18x + x2 = 0 + 99

Combine like terms: 0 + 99 = 99
18x + x2 = 99

The x term is 18x.  Take half its coefficient (9).
Square it (81) and add it to both sides.

Add '81' to each side of the equation.
18x + 81 + x2 = 99 + 81

Reorder the terms:
81 + 18x + x2 = 99 + 81

Combine like terms: 99 + 81 = 180
81 + 18x + x2 = 180

Factor a perfect square on the left side:
(x + 9)(x + 9) = 180

Calculate the square root of the right side: 13.416407865

Break this problem into two subproblems by setting 
(x + 9) equal to 13.416407865 and -13.416407865.

Subproblem 1

x + 9 = 13.416407865 Simplifying x + 9 = 13.416407865 Reorder the terms: 9 + x = 13.416407865 Solving 9 + x = 13.416407865 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-9' to each side of the equation. 9 + -9 + x = 13.416407865 + -9 Combine like terms: 9 + -9 = 0 0 + x = 13.416407865 + -9 x = 13.416407865 + -9 Combine like terms: 13.416407865 + -9 = 4.416407865 x = 4.416407865 Simplifying x = 4.416407865

Subproblem 2

x + 9 = -13.416407865 Simplifying x + 9 = -13.416407865 Reorder the terms: 9 + x = -13.416407865 Solving 9 + x = -13.416407865 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-9' to each side of the equation. 9 + -9 + x = -13.416407865 + -9 Combine like terms: 9 + -9 = 0 0 + x = -13.416407865 + -9 x = -13.416407865 + -9 Combine like terms: -13.416407865 + -9 = -22.416407865 x = -22.416407865 Simplifying x = -22.416407865

Solution

The solution to the problem is based on the solutions from the subproblems. x = {4.416407865, -22.416407865}

See similar equations:

| 4x-4+6x+4+8x-18=180 | | b+9(b+4)=-3 | | 3(2+9)=6x | | 14-15n+16=86-29n | | 7(x-2)+4=5(x+3)-3 | | 4d-43=6d-13-7d | | -2(2x+3)-4=2 | | -2=4(m+5)-3m | | 8(4x-1)=11(2x-6) | | -3(y-6)-4(9-2y)=-32-16 | | 126-4q=-14q | | 3(4c-1)-2=19 | | -16=-2x+6x+4 | | 12+f=3y | | 3-5z=18 | | 5(y+2)=17 | | 14=7r-4+2r | | 30-15=105 | | 53-7x=2x+16 | | 10x-149=3x-9 | | -3x=-153+6x | | c=30m+25 | | 5(4z-2)+9=2(8x+7) | | -1+3n=-2(1-n) | | 9(8-4y)+5y=3 | | 20=7m+6 | | 0.7(x+100)+0.9x=134 | | 3x-18=2x+5 | | 25+u=(15-10u) | | 7(3+c)=6(c-6) | | 5*-8= | | -3(7x-1)+4=21x+7 |

Equations solver categories