x^2-15x-40=

Simple and best practice solution for x^2-15x-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 x^2-15x-40= equation:


Simplifying
x2 + -15x + -40 = 0

Reorder the terms:
-40 + -15x + x2 = 0

Solving
-40 + -15x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '40' to each side of the equation.
-40 + -15x + 40 + x2 = 0 + 40

Reorder the terms:
-40 + 40 + -15x + x2 = 0 + 40

Combine like terms: -40 + 40 = 0
0 + -15x + x2 = 0 + 40
-15x + x2 = 0 + 40

Combine like terms: 0 + 40 = 40
-15x + x2 = 40

The x term is -15x.  Take half its coefficient (-7.5).
Square it (56.25) and add it to both sides.

Add '56.25' to each side of the equation.
-15x + 56.25 + x2 = 40 + 56.25

Reorder the terms:
56.25 + -15x + x2 = 40 + 56.25

Combine like terms: 40 + 56.25 = 96.25
56.25 + -15x + x2 = 96.25

Factor a perfect square on the left side:
(x + -7.5)(x + -7.5) = 96.25

Calculate the square root of the right side: 9.810708435

Break this problem into two subproblems by setting 
(x + -7.5) equal to 9.810708435 and -9.810708435.

Subproblem 1

x + -7.5 = 9.810708435 Simplifying x + -7.5 = 9.810708435 Reorder the terms: -7.5 + x = 9.810708435 Solving -7.5 + x = 9.810708435 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '7.5' to each side of the equation. -7.5 + 7.5 + x = 9.810708435 + 7.5 Combine like terms: -7.5 + 7.5 = 0.0 0.0 + x = 9.810708435 + 7.5 x = 9.810708435 + 7.5 Combine like terms: 9.810708435 + 7.5 = 17.310708435 x = 17.310708435 Simplifying x = 17.310708435

Subproblem 2

x + -7.5 = -9.810708435 Simplifying x + -7.5 = -9.810708435 Reorder the terms: -7.5 + x = -9.810708435 Solving -7.5 + x = -9.810708435 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '7.5' to each side of the equation. -7.5 + 7.5 + x = -9.810708435 + 7.5 Combine like terms: -7.5 + 7.5 = 0.0 0.0 + x = -9.810708435 + 7.5 x = -9.810708435 + 7.5 Combine like terms: -9.810708435 + 7.5 = -2.310708435 x = -2.310708435 Simplifying x = -2.310708435

Solution

The solution to the problem is based on the solutions from the subproblems. x = {17.310708435, -2.310708435}

See similar equations:

| 5x+8y=-8 | | 42+63x+63-21x=105 | | 4x+41-6x=1-8x+4 | | 4x-3+11=48 | | 1/4(x+5)=9 | | 5(2a+3)-2(a-4)=3(2a+2)+a | | 4(a-2)=8a-5 | | 8y-3y+7= | | y-9=7/5(x-1) | | -4(3a-2)=20 | | 8x-14=6x+16 | | 28+2r+3r-18=9r+18-4r-8 | | 1/16x=1/2 | | 1/16x=14/2 | | -80=6x-16y | | 11x-4=9x+18 | | 12x-(5x-12)=2+6x | | -5m-4-3=13 | | -x+28=28 | | 12-6=186 | | 7n-19=51 | | c=-12 | | 8a+3a+4a=60 | | 4x+3x+5=131 | | (6y+4)8= | | 2*16+8y=16 | | 4=29m-6 | | 8-2x=48 | | 12(y+3)=5(2y+8) | | -1/3x+8=26 | | -5u+3(u+8)=22 | | y=79+0.5x |

Equations solver categories