-2x^2+18x+9=0

Simple and best practice solution for -2x^2+18x+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 -2x^2+18x+9=0 equation:


Simplifying
-2x2 + 18x + 9 = 0

Reorder the terms:
9 + 18x + -2x2 = 0

Solving
9 + 18x + -2x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
-2 the coefficient of the squared term: 

Divide each side by '-2'.
-4.5 + -9x + x2 = 0

Move the constant term to the right:

Add '4.5' to each side of the equation.
-4.5 + -9x + 4.5 + x2 = 0 + 4.5

Reorder the terms:
-4.5 + 4.5 + -9x + x2 = 0 + 4.5

Combine like terms: -4.5 + 4.5 = 0.0
0.0 + -9x + x2 = 0 + 4.5
-9x + x2 = 0 + 4.5

Combine like terms: 0 + 4.5 = 4.5
-9x + x2 = 4.5

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 = 4.5 + 20.25

Reorder the terms:
20.25 + -9x + x2 = 4.5 + 20.25

Combine like terms: 4.5 + 20.25 = 24.75
20.25 + -9x + x2 = 24.75

Factor a perfect square on the left side:
(x + -4.5)(x + -4.5) = 24.75

Calculate the square root of the right side: 4.974937186

Break this problem into two subproblems by setting 
(x + -4.5) equal to 4.974937186 and -4.974937186.

Subproblem 1

x + -4.5 = 4.974937186 Simplifying x + -4.5 = 4.974937186 Reorder the terms: -4.5 + x = 4.974937186 Solving -4.5 + x = 4.974937186 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 = 4.974937186 + 4.5 Combine like terms: -4.5 + 4.5 = 0.0 0.0 + x = 4.974937186 + 4.5 x = 4.974937186 + 4.5 Combine like terms: 4.974937186 + 4.5 = 9.474937186 x = 9.474937186 Simplifying x = 9.474937186

Subproblem 2

x + -4.5 = -4.974937186 Simplifying x + -4.5 = -4.974937186 Reorder the terms: -4.5 + x = -4.974937186 Solving -4.5 + x = -4.974937186 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 = -4.974937186 + 4.5 Combine like terms: -4.5 + 4.5 = 0.0 0.0 + x = -4.974937186 + 4.5 x = -4.974937186 + 4.5 Combine like terms: -4.974937186 + 4.5 = -0.474937186 x = -0.474937186 Simplifying x = -0.474937186

Solution

The solution to the problem is based on the solutions from the subproblems. x = {9.474937186, -0.474937186}

See similar equations:

| 10=8x-9 | | 136=-7(8+5)+3x | | 3x+2=10x-5 | | 4+6x=70 | | -1(-2x+y)= | | 4a^3b^-3/4a^-5b^-2 | | 2x-4-3+3x=2x-8 | | 2x^3+16x^2-16x=0 | | 9+7x+3x=59 | | 15x-3=11x-7 | | .5x-6=-4 | | 2x(5+7x)=4-(x-2x+3) | | .3t+6=16 | | (z+9)*(z+9)*(z+9)=0 | | 27.2+15.7=-85.94+0.8 | | -3p-6p+14=p-8p | | -0.3x+8.69=-0.5x+7.29 | | 21/n=2/3 | | -n-2=-2n+n | | (2/x-5)-(2/x)=10/(x^2-5x) | | 4w-7/3=-3/5w-3/5 | | P^2+2PQ-24Q^2= | | (7y+4)-(2+6y)=11 | | 7d^2-63d+140=0 | | -7+x+4-5=x-8 | | -0.2x+0.6x+1=-5 | | -4p+6.4=-8.48 | | 10x-(3x-7)=5x+8 | | 21/31.5 | | x^2-xy-30y^2= | | (5c+6)*(5c-6)=0 | | 9r^2-36r-45=0 |

Equations solver categories