8x^2+9x-12=0

Simple and best practice solution for 8x^2+9x-12=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 8x^2+9x-12=0 equation:


Simplifying
8x2 + 9x + -12 = 0

Reorder the terms:
-12 + 9x + 8x2 = 0

Solving
-12 + 9x + 8x2 = 0

Solving for variable 'x'.

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

Divide each side by '8'.
-1.5 + 1.125x + x2 = 0

Move the constant term to the right:

Add '1.5' to each side of the equation.
-1.5 + 1.125x + 1.5 + x2 = 0 + 1.5

Reorder the terms:
-1.5 + 1.5 + 1.125x + x2 = 0 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + 1.125x + x2 = 0 + 1.5
1.125x + x2 = 0 + 1.5

Combine like terms: 0 + 1.5 = 1.5
1.125x + x2 = 1.5

The x term is 1.125x.  Take half its coefficient (0.5625).
Square it (0.31640625) and add it to both sides.

Add '0.31640625' to each side of the equation.
1.125x + 0.31640625 + x2 = 1.5 + 0.31640625

Reorder the terms:
0.31640625 + 1.125x + x2 = 1.5 + 0.31640625

Combine like terms: 1.5 + 0.31640625 = 1.81640625
0.31640625 + 1.125x + x2 = 1.81640625

Factor a perfect square on the left side:
(x + 0.5625)(x + 0.5625) = 1.81640625

Calculate the square root of the right side: 1.347741166

Break this problem into two subproblems by setting 
(x + 0.5625) equal to 1.347741166 and -1.347741166.

Subproblem 1

x + 0.5625 = 1.347741166 Simplifying x + 0.5625 = 1.347741166 Reorder the terms: 0.5625 + x = 1.347741166 Solving 0.5625 + x = 1.347741166 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5625' to each side of the equation. 0.5625 + -0.5625 + x = 1.347741166 + -0.5625 Combine like terms: 0.5625 + -0.5625 = 0.0000 0.0000 + x = 1.347741166 + -0.5625 x = 1.347741166 + -0.5625 Combine like terms: 1.347741166 + -0.5625 = 0.785241166 x = 0.785241166 Simplifying x = 0.785241166

Subproblem 2

x + 0.5625 = -1.347741166 Simplifying x + 0.5625 = -1.347741166 Reorder the terms: 0.5625 + x = -1.347741166 Solving 0.5625 + x = -1.347741166 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5625' to each side of the equation. 0.5625 + -0.5625 + x = -1.347741166 + -0.5625 Combine like terms: 0.5625 + -0.5625 = 0.0000 0.0000 + x = -1.347741166 + -0.5625 x = -1.347741166 + -0.5625 Combine like terms: -1.347741166 + -0.5625 = -1.910241166 x = -1.910241166 Simplifying x = -1.910241166

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.785241166, -1.910241166}

See similar equations:

| z/10-9=2 | | 6x+26=x | | X+20=62 | | 2n^2+4n-12=-6 | | y=0.15x+60 | | 18x-35=12x-25 | | 5-t-3= | | 12x+y=29 | | 3(y-5)=8y | | s-15=-49 | | a^2+16a+63= | | -y=1-2x | | 32=2(x+1)(x+1) | | 5x-3-3x=3+4 | | 2x^3+12x^2=-8x | | 1/4(8x-16)=8x-14 | | 7x-4x-5=7+3 | | 8k^2-41k+5=0 | | 50-32t^2= | | 3n-2(2n+8)=4(2n+5) | | 220/10=x/550 | | 2x+3x-4=15+1 | | 3x+2(2x-5)=5x+2x-6 | | -7x+6-3x=40-30+10-15 | | Log(x+2)=9 | | 8x+9-8=17 | | 45x+1=23x | | 5(x-6)+2x=4x-5-7 | | 7+6x+7x=-84 | | (8x-6)+(7x+9)= | | m+42=5m-10 | | (8x+6)+(7x+9)= |

Equations solver categories