7x^2-9x-1=0

Simple and best practice solution for 7x^2-9x-1=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 7x^2-9x-1=0 equation:


Simplifying
7x2 + -9x + -1 = 0

Reorder the terms:
-1 + -9x + 7x2 = 0

Solving
-1 + -9x + 7x2 = 0

Solving for variable 'x'.

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

Divide each side by '7'.
-0.1428571429 + -1.285714286x + x2 = 0

Move the constant term to the right:

Add '0.1428571429' to each side of the equation.
-0.1428571429 + -1.285714286x + 0.1428571429 + x2 = 0 + 0.1428571429

Reorder the terms:
-0.1428571429 + 0.1428571429 + -1.285714286x + x2 = 0 + 0.1428571429

Combine like terms: -0.1428571429 + 0.1428571429 = 0.0000000000
0.0000000000 + -1.285714286x + x2 = 0 + 0.1428571429
-1.285714286x + x2 = 0 + 0.1428571429

Combine like terms: 0 + 0.1428571429 = 0.1428571429
-1.285714286x + x2 = 0.1428571429

The x term is -1.285714286x.  Take half its coefficient (-0.642857143).
Square it (0.4132653063) and add it to both sides.

Add '0.4132653063' to each side of the equation.
-1.285714286x + 0.4132653063 + x2 = 0.1428571429 + 0.4132653063

Reorder the terms:
0.4132653063 + -1.285714286x + x2 = 0.1428571429 + 0.4132653063

Combine like terms: 0.1428571429 + 0.4132653063 = 0.5561224492
0.4132653063 + -1.285714286x + x2 = 0.5561224492

Factor a perfect square on the left side:
(x + -0.642857143)(x + -0.642857143) = 0.5561224492

Calculate the square root of the right side: 0.745736179

Break this problem into two subproblems by setting 
(x + -0.642857143) equal to 0.745736179 and -0.745736179.

Subproblem 1

x + -0.642857143 = 0.745736179 Simplifying x + -0.642857143 = 0.745736179 Reorder the terms: -0.642857143 + x = 0.745736179 Solving -0.642857143 + x = 0.745736179 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.642857143' to each side of the equation. -0.642857143 + 0.642857143 + x = 0.745736179 + 0.642857143 Combine like terms: -0.642857143 + 0.642857143 = 0.000000000 0.000000000 + x = 0.745736179 + 0.642857143 x = 0.745736179 + 0.642857143 Combine like terms: 0.745736179 + 0.642857143 = 1.388593322 x = 1.388593322 Simplifying x = 1.388593322

Subproblem 2

x + -0.642857143 = -0.745736179 Simplifying x + -0.642857143 = -0.745736179 Reorder the terms: -0.642857143 + x = -0.745736179 Solving -0.642857143 + x = -0.745736179 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.642857143' to each side of the equation. -0.642857143 + 0.642857143 + x = -0.745736179 + 0.642857143 Combine like terms: -0.642857143 + 0.642857143 = 0.000000000 0.000000000 + x = -0.745736179 + 0.642857143 x = -0.745736179 + 0.642857143 Combine like terms: -0.745736179 + 0.642857143 = -0.102879036 x = -0.102879036 Simplifying x = -0.102879036

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.388593322, -0.102879036}

See similar equations:

| 4c^2-9p^2= | | -(2q+8)+3(2q+7)-2q= | | e-3=2 | | 5b=15 | | -(2y+2)+3(2y+3)-2y= | | x^2-9y^2= | | x^2+76x-11552=0 | | .25(12+4p)-.5(8+2p)= | | 1-p-p^2+p^3= | | .43x+6=3x | | .73x+6=3x | | .25(16+4x)-.5(6+2x)= | | 20x^2-10x^3+15x^4= | | t+4=14 | | -6x+12y=1 | | x^2-10x-4=20 | | s=3+0.75s | | 1.06w-3=.71 | | -15*45n=45n*-30 | | 7.8m+2=165.8 | | 36p^3q-49pq^3=0 | | c^2+12c+32=0 | | 6x^2-2x+9=x+2 | | y=x^5-9x^4+278x^3+5x^2 | | 12n^4-36n^2+27=0 | | (y-3)-(y+7)=8y | | v^2=8-2v | | 25x^2+5x+2=0 | | 10x^2+5x+2=0 | | 64x^2-4y^2=0 | | xy^3-81xyz^2=0 | | 50r^2-8=0 |

Equations solver categories