2x^2+15x-9=0

Simple and best practice solution for 2x^2+15x-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+15x-9=0 equation:


Simplifying
2x2 + 15x + -9 = 0

Reorder the terms:
-9 + 15x + 2x2 = 0

Solving
-9 + 15x + 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 + 7.5x + x2 = 0

Move the constant term to the right:

Add '4.5' to each side of the equation.
-4.5 + 7.5x + 4.5 + x2 = 0 + 4.5

Reorder the terms:
-4.5 + 4.5 + 7.5x + x2 = 0 + 4.5

Combine like terms: -4.5 + 4.5 = 0.0
0.0 + 7.5x + x2 = 0 + 4.5
7.5x + x2 = 0 + 4.5

Combine like terms: 0 + 4.5 = 4.5
7.5x + x2 = 4.5

The x term is 7.5x.  Take half its coefficient (3.75).
Square it (14.0625) and add it to both sides.

Add '14.0625' to each side of the equation.
7.5x + 14.0625 + x2 = 4.5 + 14.0625

Reorder the terms:
14.0625 + 7.5x + x2 = 4.5 + 14.0625

Combine like terms: 4.5 + 14.0625 = 18.5625
14.0625 + 7.5x + x2 = 18.5625

Factor a perfect square on the left side:
(x + 3.75)(x + 3.75) = 18.5625

Calculate the square root of the right side: 4.308421985

Break this problem into two subproblems by setting 
(x + 3.75) equal to 4.308421985 and -4.308421985.

Subproblem 1

x + 3.75 = 4.308421985 Simplifying x + 3.75 = 4.308421985 Reorder the terms: 3.75 + x = 4.308421985 Solving 3.75 + x = 4.308421985 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-3.75' to each side of the equation. 3.75 + -3.75 + x = 4.308421985 + -3.75 Combine like terms: 3.75 + -3.75 = 0.00 0.00 + x = 4.308421985 + -3.75 x = 4.308421985 + -3.75 Combine like terms: 4.308421985 + -3.75 = 0.558421985 x = 0.558421985 Simplifying x = 0.558421985

Subproblem 2

x + 3.75 = -4.308421985 Simplifying x + 3.75 = -4.308421985 Reorder the terms: 3.75 + x = -4.308421985 Solving 3.75 + x = -4.308421985 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-3.75' to each side of the equation. 3.75 + -3.75 + x = -4.308421985 + -3.75 Combine like terms: 3.75 + -3.75 = 0.00 0.00 + x = -4.308421985 + -3.75 x = -4.308421985 + -3.75 Combine like terms: -4.308421985 + -3.75 = -8.058421985 x = -8.058421985 Simplifying x = -8.058421985

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.558421985, -8.058421985}

See similar equations:

| (x^2-3)/4x | | 34x+30y+25z=89 | | -1x^2+3x+3=0 | | -19x=475 | | 7x^2+15x-3=0 | | 16b-3(b-7)= | | 12=a-3.1 | | -18+n=-27 | | 10x=2x^2+2x | | 5/12-2) | | 4.3t-21t-2.3=7.6 | | (x)=x^3+2x^2+4x+8 | | S=1/2at2 | | S=1/2at2= | | 10x=x^2+3x+2 | | f(28)=24 | | 35+0.40m=20+0.55m | | 6(8x-2)=200 | | d(14)=7 | | 32x^2-24x+4=0 | | 6+4=2110 | | 9(2x+1)=100 | | 25x^2-30x+h=0 | | (4x-8)(x+5)=(5x-2)(x-2) | | 3(9x+5)=75 | | 2(2v-4)=4(3-v)-44 | | 8(x+3)=2(x+12)+10 | | 3^2/2*4 | | 3^2/4*2 | | 6x^4-11x+3=0 | | 50=10+5ln(3x+6) | | y=-x^2+4x+11 |

Equations solver categories