-1x-12=x^2-3x+7x-21

Simple and best practice solution for -1x-12=x^2-3x+7x-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 -1x-12=x^2-3x+7x-21 equation:


Simplifying
-1x + -12 = x2 + -3x + 7x + -21

Reorder the terms:
-12 + -1x = x2 + -3x + 7x + -21

Reorder the terms:
-12 + -1x = -21 + -3x + 7x + x2

Combine like terms: -3x + 7x = 4x
-12 + -1x = -21 + 4x + x2

Solving
-12 + -1x = -21 + 4x + x2

Solving for variable 'x'.

Reorder the terms:
-12 + 21 + -1x + -4x + -1x2 = -21 + 4x + x2 + 21 + -4x + -1x2

Combine like terms: -12 + 21 = 9
9 + -1x + -4x + -1x2 = -21 + 4x + x2 + 21 + -4x + -1x2

Combine like terms: -1x + -4x = -5x
9 + -5x + -1x2 = -21 + 4x + x2 + 21 + -4x + -1x2

Reorder the terms:
9 + -5x + -1x2 = -21 + 21 + 4x + -4x + x2 + -1x2

Combine like terms: -21 + 21 = 0
9 + -5x + -1x2 = 0 + 4x + -4x + x2 + -1x2
9 + -5x + -1x2 = 4x + -4x + x2 + -1x2

Combine like terms: 4x + -4x = 0
9 + -5x + -1x2 = 0 + x2 + -1x2
9 + -5x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
9 + -5x + -1x2 = 0

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-9 + 5x + x2 = 0

Move the constant term to the right:

Add '9' to each side of the equation.
-9 + 5x + 9 + x2 = 0 + 9

Reorder the terms:
-9 + 9 + 5x + x2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + 5x + x2 = 0 + 9
5x + x2 = 0 + 9

Combine like terms: 0 + 9 = 9
5x + x2 = 9

The x term is 5x.  Take half its coefficient (2.5).
Square it (6.25) and add it to both sides.

Add '6.25' to each side of the equation.
5x + 6.25 + x2 = 9 + 6.25

Reorder the terms:
6.25 + 5x + x2 = 9 + 6.25

Combine like terms: 9 + 6.25 = 15.25
6.25 + 5x + x2 = 15.25

Factor a perfect square on the left side:
(x + 2.5)(x + 2.5) = 15.25

Calculate the square root of the right side: 3.905124838

Break this problem into two subproblems by setting 
(x + 2.5) equal to 3.905124838 and -3.905124838.

Subproblem 1

x + 2.5 = 3.905124838 Simplifying x + 2.5 = 3.905124838 Reorder the terms: 2.5 + x = 3.905124838 Solving 2.5 + x = 3.905124838 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2.5' to each side of the equation. 2.5 + -2.5 + x = 3.905124838 + -2.5 Combine like terms: 2.5 + -2.5 = 0.0 0.0 + x = 3.905124838 + -2.5 x = 3.905124838 + -2.5 Combine like terms: 3.905124838 + -2.5 = 1.405124838 x = 1.405124838 Simplifying x = 1.405124838

Subproblem 2

x + 2.5 = -3.905124838 Simplifying x + 2.5 = -3.905124838 Reorder the terms: 2.5 + x = -3.905124838 Solving 2.5 + x = -3.905124838 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2.5' to each side of the equation. 2.5 + -2.5 + x = -3.905124838 + -2.5 Combine like terms: 2.5 + -2.5 = 0.0 0.0 + x = -3.905124838 + -2.5 x = -3.905124838 + -2.5 Combine like terms: -3.905124838 + -2.5 = -6.405124838 x = -6.405124838 Simplifying x = -6.405124838

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.405124838, -6.405124838}

See similar equations:

| -(-2+8)=x | | ln(x)-ln(x-2)-ln(4)=0 | | (5r^2-3r+9)+(-2r^3-r^2+3r)=0 | | -(7+9)=x | | 9x^2-30xy-24y^2=0 | | 7v+20=9(v+2) | | 0.8(x+3)+1.8(x-2)= | | -12+[-(-5)]=x | | -1/8t7 | | 21x^4-50x^3+25x^2=0 | | 3+[-(-8)]=x | | 19+x=2(x+5) | | 3+[-(-8)]= | | 17n*(-4n^2)=0 | | 2k^2+8k-8=0 | | z/3x-5=7 | | 5-b/3ab | | 1/4(11-5x)=x+14-13/8 | | 7/12z=1/6-3/10 | | 4-79= | | 4x+4(-1)+2x=2+4 | | 1/7m=1/14-5/14 | | x^2+6x+9=2x^2+3x-1 | | [-8+5m]=53 | | 25x^2-45x^2-10x=0 | | 9+3(z-3)=-6z+5 | | 5k^2+7k-5=0 | | -4+3=-12+25 | | 3(2z-1)-3(5-4z)=3 | | x+5=-6x-15 | | 23-6x=12-7x | | x+19=2(X+5) |

Equations solver categories