2x^2-5x-9=0

Simple and best practice solution for 2x^2-5x-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^2-5x-9=0 equation:


Simplifying
2x2 + -5x + -9 = 0

Reorder the terms:
-9 + -5x + 2x2 = 0

Solving
-9 + -5x + 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 + -2.5x + x2 = 0

Move the constant term to the right:

Add '4.5' to each side of the equation.
-4.5 + -2.5x + 4.5 + x2 = 0 + 4.5

Reorder the terms:
-4.5 + 4.5 + -2.5x + x2 = 0 + 4.5

Combine like terms: -4.5 + 4.5 = 0.0
0.0 + -2.5x + x2 = 0 + 4.5
-2.5x + x2 = 0 + 4.5

Combine like terms: 0 + 4.5 = 4.5
-2.5x + x2 = 4.5

The x term is -2.5x.  Take half its coefficient (-1.25).
Square it (1.5625) and add it to both sides.

Add '1.5625' to each side of the equation.
-2.5x + 1.5625 + x2 = 4.5 + 1.5625

Reorder the terms:
1.5625 + -2.5x + x2 = 4.5 + 1.5625

Combine like terms: 4.5 + 1.5625 = 6.0625
1.5625 + -2.5x + x2 = 6.0625

Factor a perfect square on the left side:
(x + -1.25)(x + -1.25) = 6.0625

Calculate the square root of the right side: 2.46221445

Break this problem into two subproblems by setting 
(x + -1.25) equal to 2.46221445 and -2.46221445.

Subproblem 1

x + -1.25 = 2.46221445 Simplifying x + -1.25 = 2.46221445 Reorder the terms: -1.25 + x = 2.46221445 Solving -1.25 + x = 2.46221445 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.25' to each side of the equation. -1.25 + 1.25 + x = 2.46221445 + 1.25 Combine like terms: -1.25 + 1.25 = 0.00 0.00 + x = 2.46221445 + 1.25 x = 2.46221445 + 1.25 Combine like terms: 2.46221445 + 1.25 = 3.71221445 x = 3.71221445 Simplifying x = 3.71221445

Subproblem 2

x + -1.25 = -2.46221445 Simplifying x + -1.25 = -2.46221445 Reorder the terms: -1.25 + x = -2.46221445 Solving -1.25 + x = -2.46221445 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.25' to each side of the equation. -1.25 + 1.25 + x = -2.46221445 + 1.25 Combine like terms: -1.25 + 1.25 = 0.00 0.00 + x = -2.46221445 + 1.25 x = -2.46221445 + 1.25 Combine like terms: -2.46221445 + 1.25 = -1.21221445 x = -1.21221445 Simplifying x = -1.21221445

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.71221445, -1.21221445}

See similar equations:

| 198=154+7x-68 | | 3.65+e=10.74 | | 126-6x=21x+15 | | 5x+5=-47-8x | | 123-3x=5x+11 | | 53-3x=9x+17 | | 4x+5=61-4x | | 5+5x=37+x | | 3a+(2a-5)=13-2(a+2) | | (3a+4)4+6=2a | | 100x^2+300x-450=0 | | 20-2t=30 | | 48=4x | | -37+x=7 | | -18=x+9 | | 12x^6=y-3(y^6+6y) | | 4.4x+41.8=10.9-5.9x | | x^3-36=0 | | x^3-x-36=0 | | x^3-30x-36=0 | | x^3-7x-36=0 | | 8+19p-6=9p+104-7p | | 9(y+7)=9(y-2) | | 70=10log(10) | | 37=x+12 | | 76=14+b | | 56-u=37 | | 79=s+13 | | 8+q=61 | | 15j=225 | | 108=18t | | -13-9x=7x+19 |

Equations solver categories