4x^2-12x-9=0

Simple and best practice solution for 4x^2-12x-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 4x^2-12x-9=0 equation:


Simplifying
4x2 + -12x + -9 = 0

Reorder the terms:
-9 + -12x + 4x2 = 0

Solving
-9 + -12x + 4x2 = 0

Solving for variable 'x'.

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

Divide each side by '4'.
-2.25 + -3x + x2 = 0

Move the constant term to the right:

Add '2.25' to each side of the equation.
-2.25 + -3x + 2.25 + x2 = 0 + 2.25

Reorder the terms:
-2.25 + 2.25 + -3x + x2 = 0 + 2.25

Combine like terms: -2.25 + 2.25 = 0.00
0.00 + -3x + x2 = 0 + 2.25
-3x + x2 = 0 + 2.25

Combine like terms: 0 + 2.25 = 2.25
-3x + x2 = 2.25

The x term is -3x.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3x + 2.25 + x2 = 2.25 + 2.25

Reorder the terms:
2.25 + -3x + x2 = 2.25 + 2.25

Combine like terms: 2.25 + 2.25 = 4.5
2.25 + -3x + x2 = 4.5

Factor a perfect square on the left side:
(x + -1.5)(x + -1.5) = 4.5

Calculate the square root of the right side: 2.121320344

Break this problem into two subproblems by setting 
(x + -1.5) equal to 2.121320344 and -2.121320344.

Subproblem 1

x + -1.5 = 2.121320344 Simplifying x + -1.5 = 2.121320344 Reorder the terms: -1.5 + x = 2.121320344 Solving -1.5 + x = 2.121320344 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.5' to each side of the equation. -1.5 + 1.5 + x = 2.121320344 + 1.5 Combine like terms: -1.5 + 1.5 = 0.0 0.0 + x = 2.121320344 + 1.5 x = 2.121320344 + 1.5 Combine like terms: 2.121320344 + 1.5 = 3.621320344 x = 3.621320344 Simplifying x = 3.621320344

Subproblem 2

x + -1.5 = -2.121320344 Simplifying x + -1.5 = -2.121320344 Reorder the terms: -1.5 + x = -2.121320344 Solving -1.5 + x = -2.121320344 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.5' to each side of the equation. -1.5 + 1.5 + x = -2.121320344 + 1.5 Combine like terms: -1.5 + 1.5 = 0.0 0.0 + x = -2.121320344 + 1.5 x = -2.121320344 + 1.5 Combine like terms: -2.121320344 + 1.5 = -0.621320344 x = -0.621320344 Simplifying x = -0.621320344

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.621320344, -0.621320344}

See similar equations:

| a+5=-5+5 | | 0=3x-2 | | -1=3x-2 | | -2=3x-2 | | 10a^2-27ab+5b^2= | | 18.7+19.4t=18.3t | | (5x+3)(4x-7)=90 | | 9x+4=90 | | -7b-22=-(8b-2)-2b | | -12q^2+17q+5=0 | | 2x+4=-2-x | | 4x-7=90 | | 19.79+16.1p=14.4p+8.06 | | 4(4x-4)=2(8x+3) | | 5x+20=12x-64 | | -9u^2+36u=0 | | 6x-5y=15 | | (x+4)(x+7)= | | (9x+4)(5x+3)(4x-7)=180 | | (9x+4)(5x+3)(4x-7)=90 | | 2x^2+4x-1=7x^2-7x+1 | | (5X)+(4Y)=253 | | x^3+5x-6=0 | | x-42-3x=60 | | 2x^2+4x-1=7q^2-7q+1 | | 8+19t-2=8t+132-3t | | 5b+7-3b= | | -2x+4=x+2 | | 42-3x+x=60 | | 6n-3+n+17=180 | | -7.7q-14.33=-5.3q-8.01-2q | | 4h+7h-6=16 |

Equations solver categories