(x-9)(x+9)=-3x

Simple and best practice solution for (x-9)(x+9)=-3x 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-9)(x+9)=-3x equation:


Simplifying
(x + -9)(x + 9) = -3x

Reorder the terms:
(-9 + x)(x + 9) = -3x

Reorder the terms:
(-9 + x)(9 + x) = -3x

Multiply (-9 + x) * (9 + x)
(-9(9 + x) + x(9 + x)) = -3x
((9 * -9 + x * -9) + x(9 + x)) = -3x
((-81 + -9x) + x(9 + x)) = -3x
(-81 + -9x + (9 * x + x * x)) = -3x
(-81 + -9x + (9x + x2)) = -3x

Combine like terms: -9x + 9x = 0
(-81 + 0 + x2) = -3x
(-81 + x2) = -3x

Solving
-81 + x2 = -3x

Solving for variable 'x'.

Reorder the terms:
-81 + 3x + x2 = -3x + 3x

Combine like terms: -3x + 3x = 0
-81 + 3x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '81' to each side of the equation.
-81 + 3x + 81 + x2 = 0 + 81

Reorder the terms:
-81 + 81 + 3x + x2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + 3x + x2 = 0 + 81
3x + x2 = 0 + 81

Combine like terms: 0 + 81 = 81
3x + x2 = 81

The x term is 3x.  Take half its coefficient (1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
3x + 2.25 + x2 = 81 + 2.25

Reorder the terms:
2.25 + 3x + x2 = 81 + 2.25

Combine like terms: 81 + 2.25 = 83.25
2.25 + 3x + x2 = 83.25

Factor a perfect square on the left side:
(x + 1.5)(x + 1.5) = 83.25

Calculate the square root of the right side: 9.124143795

Break this problem into two subproblems by setting 
(x + 1.5) equal to 9.124143795 and -9.124143795.

Subproblem 1

x + 1.5 = 9.124143795 Simplifying x + 1.5 = 9.124143795 Reorder the terms: 1.5 + x = 9.124143795 Solving 1.5 + x = 9.124143795 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.5' to each side of the equation. 1.5 + -1.5 + x = 9.124143795 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = 9.124143795 + -1.5 x = 9.124143795 + -1.5 Combine like terms: 9.124143795 + -1.5 = 7.624143795 x = 7.624143795 Simplifying x = 7.624143795

Subproblem 2

x + 1.5 = -9.124143795 Simplifying x + 1.5 = -9.124143795 Reorder the terms: 1.5 + x = -9.124143795 Solving 1.5 + x = -9.124143795 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.5' to each side of the equation. 1.5 + -1.5 + x = -9.124143795 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = -9.124143795 + -1.5 x = -9.124143795 + -1.5 Combine like terms: -9.124143795 + -1.5 = -10.624143795 x = -10.624143795 Simplifying x = -10.624143795

Solution

The solution to the problem is based on the solutions from the subproblems. x = {7.624143795, -10.624143795}

See similar equations:

| 2x^2+5y^2=14 | | 15y+25-6y-4=3 | | 5a^2-33a+26=8 | | D-2.6=3.9 | | 5b-2+3b^2=0 | | 3x-(2x-2)=7 | | 7+8y-3+3y+5-6y= | | 12-3x+14=17 | | -30=30cosx | | 4x^2-30x-16=0 | | 35-6k=2k+3(1-8k) | | 2+a/4=6 | | 4(x-4)=-16+4x | | 5.6+x=7 | | (x+8)(x-6)=24 | | 0.2x+0.5(14-x)=3.4 | | -0.2h-3=8.6 | | 2-2y=-1/3*(y-2)-2 | | 10*cosx=0 | | 3k+220=12k+200 | | 2+a/4 | | 2(x-2)-(3x-5)=2(5x-1)-19 | | 2-2y=-1/3*(y-2) | | 1/b+3b/5b-2=o | | -4(t-7)-3(3t+1)=-14 | | 4y-6y=8 | | D=.5mw | | Y=-5/4+1 | | -4-2(2-a)=0 | | unterciox=4 | | 1.50+.10(m-2)=2.70 | | 5/8(8x+32)+1=1/2(12x-2)+17 |

Equations solver categories