9x^2-7x-8=0

Simple and best practice solution for 9x^2-7x-8=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 9x^2-7x-8=0 equation:


Simplifying
9x2 + -7x + -8 = 0

Reorder the terms:
-8 + -7x + 9x2 = 0

Solving
-8 + -7x + 9x2 = 0

Solving for variable 'x'.

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

Divide each side by '9'.
-0.8888888889 + -0.7777777778x + x2 = 0

Move the constant term to the right:

Add '0.8888888889' to each side of the equation.
-0.8888888889 + -0.7777777778x + 0.8888888889 + x2 = 0 + 0.8888888889

Reorder the terms:
-0.8888888889 + 0.8888888889 + -0.7777777778x + x2 = 0 + 0.8888888889

Combine like terms: -0.8888888889 + 0.8888888889 = 0.0000000000
0.0000000000 + -0.7777777778x + x2 = 0 + 0.8888888889
-0.7777777778x + x2 = 0 + 0.8888888889

Combine like terms: 0 + 0.8888888889 = 0.8888888889
-0.7777777778x + x2 = 0.8888888889

The x term is -0.7777777778x.  Take half its coefficient (-0.3888888889).
Square it (0.1512345679) and add it to both sides.

Add '0.1512345679' to each side of the equation.
-0.7777777778x + 0.1512345679 + x2 = 0.8888888889 + 0.1512345679

Reorder the terms:
0.1512345679 + -0.7777777778x + x2 = 0.8888888889 + 0.1512345679

Combine like terms: 0.8888888889 + 0.1512345679 = 1.0401234568
0.1512345679 + -0.7777777778x + x2 = 1.0401234568

Factor a perfect square on the left side:
(x + -0.3888888889)(x + -0.3888888889) = 1.0401234568

Calculate the square root of the right side: 1.019864431

Break this problem into two subproblems by setting 
(x + -0.3888888889) equal to 1.019864431 and -1.019864431.

Subproblem 1

x + -0.3888888889 = 1.019864431 Simplifying x + -0.3888888889 = 1.019864431 Reorder the terms: -0.3888888889 + x = 1.019864431 Solving -0.3888888889 + x = 1.019864431 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.3888888889' to each side of the equation. -0.3888888889 + 0.3888888889 + x = 1.019864431 + 0.3888888889 Combine like terms: -0.3888888889 + 0.3888888889 = 0.0000000000 0.0000000000 + x = 1.019864431 + 0.3888888889 x = 1.019864431 + 0.3888888889 Combine like terms: 1.019864431 + 0.3888888889 = 1.4087533199 x = 1.4087533199 Simplifying x = 1.4087533199

Subproblem 2

x + -0.3888888889 = -1.019864431 Simplifying x + -0.3888888889 = -1.019864431 Reorder the terms: -0.3888888889 + x = -1.019864431 Solving -0.3888888889 + x = -1.019864431 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.3888888889' to each side of the equation. -0.3888888889 + 0.3888888889 + x = -1.019864431 + 0.3888888889 Combine like terms: -0.3888888889 + 0.3888888889 = 0.0000000000 0.0000000000 + x = -1.019864431 + 0.3888888889 x = -1.019864431 + 0.3888888889 Combine like terms: -1.019864431 + 0.3888888889 = -0.6309755421 x = -0.6309755421 Simplifying x = -0.6309755421

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.4087533199, -0.6309755421}

See similar equations:

| 6x-9w*2y+5w*5x+7y= | | 3y^2=-18y | | 3p(p-10)-6(5-3p)= | | (22-4)-33= | | -0.3y+4.2=6.6 | | 2x-8x=18 | | 9a-41=1000 | | 5x=6y+90 | | 9.37-2.021=8.89 | | 6y+90=5x | | 4x^2+5x=80 | | p+4+p-3= | | 5(x+8)=4(2x+10)-3x | | 8x-4=9x-6 | | 9y+52=14y-3 | | x+u=9 | | p+4+p+3= | | 12-2x=6x+39 | | 2(x-2)+3(x-3)=2-2(2x-1)+13 | | x(13-2)+5whenx=2 | | -7y-6=-6 | | 4x+3-y=5xy-7-3y | | 5/7(35x) | | -4x*-3= | | 4ln(x+4)=16 | | 2x-(x-4)=1+3(x+2) | | -4w-19=-7 | | 3x^5+96=0 | | 8=-9y-10 | | 5h+3(11-h)=-5 | | 18m^3+27m^2-2m-8=0 | | 7.32=13.53+2.81 |

Equations solver categories