x^2+17x-81=0

Simple and best practice solution for x^2+17x-81=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+17x-81=0 equation:


Simplifying
x2 + 17x + -81 = 0

Reorder the terms:
-81 + 17x + x2 = 0

Solving
-81 + 17x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '81' to each side of the equation.
-81 + 17x + 81 + x2 = 0 + 81

Reorder the terms:
-81 + 81 + 17x + x2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + 17x + x2 = 0 + 81
17x + x2 = 0 + 81

Combine like terms: 0 + 81 = 81
17x + x2 = 81

The x term is 17x.  Take half its coefficient (8.5).
Square it (72.25) and add it to both sides.

Add '72.25' to each side of the equation.
17x + 72.25 + x2 = 81 + 72.25

Reorder the terms:
72.25 + 17x + x2 = 81 + 72.25

Combine like terms: 81 + 72.25 = 153.25
72.25 + 17x + x2 = 153.25

Factor a perfect square on the left side:
(x + 8.5)(x + 8.5) = 153.25

Calculate the square root of the right side: 12.379418403

Break this problem into two subproblems by setting 
(x + 8.5) equal to 12.379418403 and -12.379418403.

Subproblem 1

x + 8.5 = 12.379418403 Simplifying x + 8.5 = 12.379418403 Reorder the terms: 8.5 + x = 12.379418403 Solving 8.5 + x = 12.379418403 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-8.5' to each side of the equation. 8.5 + -8.5 + x = 12.379418403 + -8.5 Combine like terms: 8.5 + -8.5 = 0.0 0.0 + x = 12.379418403 + -8.5 x = 12.379418403 + -8.5 Combine like terms: 12.379418403 + -8.5 = 3.879418403 x = 3.879418403 Simplifying x = 3.879418403

Subproblem 2

x + 8.5 = -12.379418403 Simplifying x + 8.5 = -12.379418403 Reorder the terms: 8.5 + x = -12.379418403 Solving 8.5 + x = -12.379418403 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-8.5' to each side of the equation. 8.5 + -8.5 + x = -12.379418403 + -8.5 Combine like terms: 8.5 + -8.5 = 0.0 0.0 + x = -12.379418403 + -8.5 x = -12.379418403 + -8.5 Combine like terms: -12.379418403 + -8.5 = -20.879418403 x = -20.879418403 Simplifying x = -20.879418403

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.879418403, -20.879418403}

See similar equations:

| 9+9p=27 | | 34=35 | | 25+5x=40+3x | | y^2-4y+10=0 | | y^2-7y+7=0 | | 7a-7ab-2-9ab+7a= | | 5m-2=4m+4 | | 4.8+1.3n=1.29 | | -8y=17 | | (9a-1)(a+7)=0 | | 3-3*6+2=b | | 6(3y-y)-3(2y)=26 | | 40w^2-14w-6=0 | | 7+4x=21+7x | | 19x^2-14x-1=0 | | 38+(7x+1)=10x+9 | | 8x-1=71 | | 12-1m=-7 | | 4x+27=8x+7 | | 75w^2-10w-5=0 | | 1+x+0.4x= | | 2a+4b=32 | | 4x-3=2x-15 | | 8x-19=x+16 | | 12x-3=-8 | | x^2+9x+14=-3 | | 80y^2-68y+12=0 | | 0.5x*0.2121=0.08 | | 4x-20=1x+10 | | 4+16s=-44 | | .05=0.5x+4 | | [x^2+9x+14]=-3 |

Equations solver categories