21x^2+26x-8=0

Simple and best practice solution for 21x^2+26x-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 21x^2+26x-8=0 equation:


Simplifying
21x2 + 26x + -8 = 0

Reorder the terms:
-8 + 26x + 21x2 = 0

Solving
-8 + 26x + 21x2 = 0

Solving for variable 'x'.

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

Divide each side by '21'.
-0.380952381 + 1.238095238x + x2 = 0

Move the constant term to the right:

Add '0.380952381' to each side of the equation.
-0.380952381 + 1.238095238x + 0.380952381 + x2 = 0 + 0.380952381

Reorder the terms:
-0.380952381 + 0.380952381 + 1.238095238x + x2 = 0 + 0.380952381

Combine like terms: -0.380952381 + 0.380952381 = 0.000000000
0.000000000 + 1.238095238x + x2 = 0 + 0.380952381
1.238095238x + x2 = 0 + 0.380952381

Combine like terms: 0 + 0.380952381 = 0.380952381
1.238095238x + x2 = 0.380952381

The x term is 1.238095238x.  Take half its coefficient (0.619047619).
Square it (0.3832199546) and add it to both sides.

Add '0.3832199546' to each side of the equation.
1.238095238x + 0.3832199546 + x2 = 0.380952381 + 0.3832199546

Reorder the terms:
0.3832199546 + 1.238095238x + x2 = 0.380952381 + 0.3832199546

Combine like terms: 0.380952381 + 0.3832199546 = 0.7641723356
0.3832199546 + 1.238095238x + x2 = 0.7641723356

Factor a perfect square on the left side:
(x + 0.619047619)(x + 0.619047619) = 0.7641723356

Calculate the square root of the right side: 0.874169512

Break this problem into two subproblems by setting 
(x + 0.619047619) equal to 0.874169512 and -0.874169512.

Subproblem 1

x + 0.619047619 = 0.874169512 Simplifying x + 0.619047619 = 0.874169512 Reorder the terms: 0.619047619 + x = 0.874169512 Solving 0.619047619 + x = 0.874169512 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.619047619' to each side of the equation. 0.619047619 + -0.619047619 + x = 0.874169512 + -0.619047619 Combine like terms: 0.619047619 + -0.619047619 = 0.000000000 0.000000000 + x = 0.874169512 + -0.619047619 x = 0.874169512 + -0.619047619 Combine like terms: 0.874169512 + -0.619047619 = 0.255121893 x = 0.255121893 Simplifying x = 0.255121893

Subproblem 2

x + 0.619047619 = -0.874169512 Simplifying x + 0.619047619 = -0.874169512 Reorder the terms: 0.619047619 + x = -0.874169512 Solving 0.619047619 + x = -0.874169512 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.619047619' to each side of the equation. 0.619047619 + -0.619047619 + x = -0.874169512 + -0.619047619 Combine like terms: 0.619047619 + -0.619047619 = 0.000000000 0.000000000 + x = -0.874169512 + -0.619047619 x = -0.874169512 + -0.619047619 Combine like terms: -0.874169512 + -0.619047619 = -1.493217131 x = -1.493217131 Simplifying x = -1.493217131

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.255121893, -1.493217131}

See similar equations:

| 2(1-6n)=-14+4n | | -17.406=1-5.11m+5.1 | | 6+r=-8(r+6) | | ln(x)=0.2 | | 24x^2-1=-2x | | 5.5b-5+6.7=13.25 | | 8x+3y=39 | | -8(4p-6)-7=-119 | | 108=18-30r | | (x^0.4)/16=32/x^2.6 | | 10t+-5=-35 | | 3t^6/5^-5u^-2 | | 146.005=3.5(3.2-6.9n)+0.5n | | e^4x=50 | | -c-7=4 | | 10s-30=-136 | | 247=13r | | 5x+5.55=8x | | f(x)=4.2x^2+6x-1 | | 8x+3x+55=77 | | 6−2/5x=−1 | | Y-9=-2/3*6 | | 7xsquared-14x=-7 | | Y-9=-2/3x6 | | 1/7x3/6 | | 7=lx+9l+7 | | -a+7=2a-a | | 25y^2-45y=0 | | (15y-18)+(3y+6)= | | 6(b+14)-14=9 | | 16ax-25by+20bx-20ay= | | nsquared+7n+15=5 |

Equations solver categories