0=x^2+9x-40

Simple and best practice solution for 0=x^2+9x-40 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 0=x^2+9x-40 equation:


Simplifying
0 = x2 + 9x + -40

Reorder the terms:
0 = -40 + 9x + x2

Solving
0 = -40 + 9x + x2

Solving for variable 'x'.

Combine like terms: 0 + 40 = 40
40 + -9x + -1x2 = -40 + 9x + x2 + 40 + -9x + -1x2

Reorder the terms:
40 + -9x + -1x2 = -40 + 40 + 9x + -9x + x2 + -1x2

Combine like terms: -40 + 40 = 0
40 + -9x + -1x2 = 0 + 9x + -9x + x2 + -1x2
40 + -9x + -1x2 = 9x + -9x + x2 + -1x2

Combine like terms: 9x + -9x = 0
40 + -9x + -1x2 = 0 + x2 + -1x2
40 + -9x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
40 + -9x + -1x2 = 0

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

Divide each side by '-1'.
-40 + 9x + x2 = 0

Move the constant term to the right:

Add '40' to each side of the equation.
-40 + 9x + 40 + x2 = 0 + 40

Reorder the terms:
-40 + 40 + 9x + x2 = 0 + 40

Combine like terms: -40 + 40 = 0
0 + 9x + x2 = 0 + 40
9x + x2 = 0 + 40

Combine like terms: 0 + 40 = 40
9x + x2 = 40

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 = 40 + 20.25

Reorder the terms:
20.25 + 9x + x2 = 40 + 20.25

Combine like terms: 40 + 20.25 = 60.25
20.25 + 9x + x2 = 60.25

Factor a perfect square on the left side:
(x + 4.5)(x + 4.5) = 60.25

Calculate the square root of the right side: 7.762087348

Break this problem into two subproblems by setting 
(x + 4.5) equal to 7.762087348 and -7.762087348.

Subproblem 1

x + 4.5 = 7.762087348 Simplifying x + 4.5 = 7.762087348 Reorder the terms: 4.5 + x = 7.762087348 Solving 4.5 + x = 7.762087348 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 = 7.762087348 + -4.5 Combine like terms: 4.5 + -4.5 = 0.0 0.0 + x = 7.762087348 + -4.5 x = 7.762087348 + -4.5 Combine like terms: 7.762087348 + -4.5 = 3.262087348 x = 3.262087348 Simplifying x = 3.262087348

Subproblem 2

x + 4.5 = -7.762087348 Simplifying x + 4.5 = -7.762087348 Reorder the terms: 4.5 + x = -7.762087348 Solving 4.5 + x = -7.762087348 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 = -7.762087348 + -4.5 Combine like terms: 4.5 + -4.5 = 0.0 0.0 + x = -7.762087348 + -4.5 x = -7.762087348 + -4.5 Combine like terms: -7.762087348 + -4.5 = -12.262087348 x = -12.262087348 Simplifying x = -12.262087348

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.262087348, -12.262087348}

See similar equations:

| f(x)=5x^2-7x+8 | | 3.9-17.9=2.3 | | 32=t | | -6x-3y=12 | | n=7000000(1+0.05) | | z-16=-4 | | X*X-4=192 | | 10x-4(2x-1)=-6+8 | | sin(4x)+sin(x)=0 | | 225=9*4x | | 2+0.3=3.3 | | 11xwhat=121 | | n=7000000(1+0.05)12 | | 17+x=22 | | x+3yi=5+2i | | y=2ln(4x) | | 6(a+-b)+-5(2a+4b)= | | 3x+6=3x+21 | | 3(s+7)-(s+1)=22s | | -35n+25+3n= | | 7(10x-5)=315 | | 4x+67=7x+80 | | .6w-0.4=-6+w | | 48=3(x-4) | | 9(9n+3)=7n-3 | | 10(8x-11)=370 | | 3x+(2x-10)=190 | | 8(4n-2n)+n+1+2n-3= | | 5(6x+13)=245 | | 11y=45 | | 8+6m+m-2= | | 3-7x^2+9x= |

Equations solver categories