3=x^2-9x

Simple and best practice solution for 3=x^2-9x 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 3=x^2-9x equation:


Simplifying
3 = x2 + -9x

Reorder the terms:
3 = -9x + x2

Solving
3 = -9x + x2

Solving for variable 'x'.

Reorder the terms:
3 + 9x + -1x2 = -9x + 9x + x2 + -1x2

Combine like terms: -9x + 9x = 0
3 + 9x + -1x2 = 0 + x2 + -1x2
3 + 9x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
3 + 9x + -1x2 = 0

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

Divide each side by '-1'.
-3 + -9x + x2 = 0

Move the constant term to the right:

Add '3' to each side of the equation.
-3 + -9x + 3 + x2 = 0 + 3

Reorder the terms:
-3 + 3 + -9x + x2 = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -9x + x2 = 0 + 3
-9x + x2 = 0 + 3

Combine like terms: 0 + 3 = 3
-9x + x2 = 3

The x term is -9x.  Take half its coefficient (-4.5).
Square it (20.25) and add it to both sides.

Add '20.25' to each side of the equation.
-9x + 20.25 + x2 = 3 + 20.25

Reorder the terms:
20.25 + -9x + x2 = 3 + 20.25

Combine like terms: 3 + 20.25 = 23.25
20.25 + -9x + x2 = 23.25

Factor a perfect square on the left side:
(x + -4.5)(x + -4.5) = 23.25

Calculate the square root of the right side: 4.82182538

Break this problem into two subproblems by setting 
(x + -4.5) equal to 4.82182538 and -4.82182538.

Subproblem 1

x + -4.5 = 4.82182538 Simplifying x + -4.5 = 4.82182538 Reorder the terms: -4.5 + x = 4.82182538 Solving -4.5 + x = 4.82182538 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '4.5' to each side of the equation. -4.5 + 4.5 + x = 4.82182538 + 4.5 Combine like terms: -4.5 + 4.5 = 0.0 0.0 + x = 4.82182538 + 4.5 x = 4.82182538 + 4.5 Combine like terms: 4.82182538 + 4.5 = 9.32182538 x = 9.32182538 Simplifying x = 9.32182538

Subproblem 2

x + -4.5 = -4.82182538 Simplifying x + -4.5 = -4.82182538 Reorder the terms: -4.5 + x = -4.82182538 Solving -4.5 + x = -4.82182538 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '4.5' to each side of the equation. -4.5 + 4.5 + x = -4.82182538 + 4.5 Combine like terms: -4.5 + 4.5 = 0.0 0.0 + x = -4.82182538 + 4.5 x = -4.82182538 + 4.5 Combine like terms: -4.82182538 + 4.5 = -0.32182538 x = -0.32182538 Simplifying x = -0.32182538

Solution

The solution to the problem is based on the solutions from the subproblems. x = {9.32182538, -0.32182538}

See similar equations:

| 3=x^2+9x | | 20y+2=46fraction | | c+5=c+8 | | -20/24 | | q=0.5*p | | q=0.5p | | 2x^2-5x+x^2+4x+8= | | 9h+6=36 | | (x+1)(x+1)=12 | | 3(3x-7)=6(4-x) | | c-7.6+9.4=-8.4 | | -16x(x)+28x+8=0 | | x-2/-2=6 | | B-8=ax-3x | | x/y=0.666666667 | | .5(x+4)(x)=35 | | .5(x+4)(x)=0 | | 3(5-y)/5-6y | | 4/5-1/15x4/3 | | x^2(180-x)=561600 | | 8x+48=9x+36 | | P/9=32 | | 8x-24=12x-36 | | a+12=b-18 | | 8x+24=12x+36 | | f(x)=7x^3-x^2+4x | | -5x+7=-2x-5 | | =6/7m=-24 | | -x+3+4x=0 | | 3x+4x-8= | | 3x-y=45 | | 6(x-2)-8(x-3)=2(4+x) |

Equations solver categories