4x^2-2x-21=

Simple and best practice solution for 4x^2-2x-21= 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 4x^2-2x-21= equation:


Simplifying
4x2 + -2x + -21 = 0

Reorder the terms:
-21 + -2x + 4x2 = 0

Solving
-21 + -2x + 4x2 = 0

Solving for variable 'x'.

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

Divide each side by '4'.
-5.25 + -0.5x + x2 = 0

Move the constant term to the right:

Add '5.25' to each side of the equation.
-5.25 + -0.5x + 5.25 + x2 = 0 + 5.25

Reorder the terms:
-5.25 + 5.25 + -0.5x + x2 = 0 + 5.25

Combine like terms: -5.25 + 5.25 = 0.00
0.00 + -0.5x + x2 = 0 + 5.25
-0.5x + x2 = 0 + 5.25

Combine like terms: 0 + 5.25 = 5.25
-0.5x + x2 = 5.25

The x term is -0.5x.  Take half its coefficient (-0.25).
Square it (0.0625) and add it to both sides.

Add '0.0625' to each side of the equation.
-0.5x + 0.0625 + x2 = 5.25 + 0.0625

Reorder the terms:
0.0625 + -0.5x + x2 = 5.25 + 0.0625

Combine like terms: 5.25 + 0.0625 = 5.3125
0.0625 + -0.5x + x2 = 5.3125

Factor a perfect square on the left side:
(x + -0.25)(x + -0.25) = 5.3125

Calculate the square root of the right side: 2.304886114

Break this problem into two subproblems by setting 
(x + -0.25) equal to 2.304886114 and -2.304886114.

Subproblem 1

x + -0.25 = 2.304886114 Simplifying x + -0.25 = 2.304886114 Reorder the terms: -0.25 + x = 2.304886114 Solving -0.25 + x = 2.304886114 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.25' to each side of the equation. -0.25 + 0.25 + x = 2.304886114 + 0.25 Combine like terms: -0.25 + 0.25 = 0.00 0.00 + x = 2.304886114 + 0.25 x = 2.304886114 + 0.25 Combine like terms: 2.304886114 + 0.25 = 2.554886114 x = 2.554886114 Simplifying x = 2.554886114

Subproblem 2

x + -0.25 = -2.304886114 Simplifying x + -0.25 = -2.304886114 Reorder the terms: -0.25 + x = -2.304886114 Solving -0.25 + x = -2.304886114 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.25' to each side of the equation. -0.25 + 0.25 + x = -2.304886114 + 0.25 Combine like terms: -0.25 + 0.25 = 0.00 0.00 + x = -2.304886114 + 0.25 x = -2.304886114 + 0.25 Combine like terms: -2.304886114 + 0.25 = -2.054886114 x = -2.054886114 Simplifying x = -2.054886114

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.554886114, -2.054886114}

See similar equations:

| x-2+2-3=1-4 | | 2x^5y^2+16x^2y^3= | | 3X=-16.3 | | s-19=50 | | X=-16.3 | | 39x+3+20x=360 | | 3-2x-7-(-7)= | | 12n^2+41n+24=0 | | 2x+12=32-6x | | 24n^3+52n^2-20n=0 | | 0.4x=2.4 | | -1x-6x=6x-2x | | (-5-c)(-1)= | | 9x+13+19x-7=180 | | .5(-12m+38)= | | 179=44+45H | | 3(2-x)+x=5(2x-1)+2 | | 1P+4=-16 | | 6h=72 | | -10x^2+15x^2=0 | | 2x-10=6-6x | | 2(4m+6)= | | 8y^2+18y-35=0 | | 26.1=19.8-4t | | 564984x^101654949=3 | | 4x^2+14x+12= | | -6x+4(x-8)=-30 | | 4x-2+2x+18=180 | | 2.5x+15.37=165.45 | | 33+(-123)+x=60 | | 2.5(17.5)+15.37=c | | 2c-15=6c+100 |

Equations solver categories