x^2+4x-21=2

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


Simplifying
x2 + 4x + -21 = 2

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

Solving
-21 + 4x + x2 = 2

Solving for variable 'x'.

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

Combine like terms: -21 + -2 = -23
-23 + 4x + x2 = 2 + -2

Combine like terms: 2 + -2 = 0
-23 + 4x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '23' to each side of the equation.
-23 + 4x + 23 + x2 = 0 + 23

Reorder the terms:
-23 + 23 + 4x + x2 = 0 + 23

Combine like terms: -23 + 23 = 0
0 + 4x + x2 = 0 + 23
4x + x2 = 0 + 23

Combine like terms: 0 + 23 = 23
4x + x2 = 23

The x term is 4x.  Take half its coefficient (2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
4x + 4 + x2 = 23 + 4

Reorder the terms:
4 + 4x + x2 = 23 + 4

Combine like terms: 23 + 4 = 27
4 + 4x + x2 = 27

Factor a perfect square on the left side:
(x + 2)(x + 2) = 27

Calculate the square root of the right side: 5.196152423

Break this problem into two subproblems by setting 
(x + 2) equal to 5.196152423 and -5.196152423.

Subproblem 1

x + 2 = 5.196152423 Simplifying x + 2 = 5.196152423 Reorder the terms: 2 + x = 5.196152423 Solving 2 + x = 5.196152423 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = 5.196152423 + -2 Combine like terms: 2 + -2 = 0 0 + x = 5.196152423 + -2 x = 5.196152423 + -2 Combine like terms: 5.196152423 + -2 = 3.196152423 x = 3.196152423 Simplifying x = 3.196152423

Subproblem 2

x + 2 = -5.196152423 Simplifying x + 2 = -5.196152423 Reorder the terms: 2 + x = -5.196152423 Solving 2 + x = -5.196152423 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = -5.196152423 + -2 Combine like terms: 2 + -2 = 0 0 + x = -5.196152423 + -2 x = -5.196152423 + -2 Combine like terms: -5.196152423 + -2 = -7.196152423 x = -7.196152423 Simplifying x = -7.196152423

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.196152423, -7.196152423}

See similar equations:

| 36/p=p-5 | | 0=-25x^2+15x+125 | | 28=(w+2)(w) | | 6x^2+22x=-20 | | 6x+5=-2x^2 | | 3.4(x-2a)-2.1(x+3)=2.4 | | 61x^2+1=y^2 | | x+x+68+2x=180 | | -7m^2-2m-28=-8m^2-4 | | 5x+3+5x-3=90 | | 2(x)+x+68=180 | | 2x+x+68=180 | | 5x+3+5x-3=180 | | 28-19=3(x-4) | | 1/8(8x-6)=-1/3-7/3 | | 5-5lnx=6 | | 5-lnx=6 | | -4-(9*-4+8)= | | 4x-2(x-4)=12 | | x-12/x-8 | | 56+6y-14=17y-14-3y | | (2x-1)/4=1/4 | | x+2=x^2+4 | | 2x^2-21=x | | 3x+3x+5+(7x+6)=180 | | 52=.5((x+6)*(x+5)) | | x+21+3x=-33-3x-37 | | -1.8x-4=-1.1x+3 | | 18*8.5= | | abs(4y-2)=abs(4y+5) | | f(x)=10-2x/3 | | 5g+1h=5 |

Equations solver categories