x^2+15x-13=

Simple and best practice solution for x^2+15x-13= 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-13= equation:


Simplifying
x2 + 15x + -13 = 0

Reorder the terms:
-13 + 15x + x2 = 0

Solving
-13 + 15x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '13' to each side of the equation.
-13 + 15x + 13 + x2 = 0 + 13

Reorder the terms:
-13 + 13 + 15x + x2 = 0 + 13

Combine like terms: -13 + 13 = 0
0 + 15x + x2 = 0 + 13
15x + x2 = 0 + 13

Combine like terms: 0 + 13 = 13
15x + x2 = 13

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 = 13 + 56.25

Reorder the terms:
56.25 + 15x + x2 = 13 + 56.25

Combine like terms: 13 + 56.25 = 69.25
56.25 + 15x + x2 = 69.25

Factor a perfect square on the left side:
(x + 7.5)(x + 7.5) = 69.25

Calculate the square root of the right side: 8.321658489

Break this problem into two subproblems by setting 
(x + 7.5) equal to 8.321658489 and -8.321658489.

Subproblem 1

x + 7.5 = 8.321658489 Simplifying x + 7.5 = 8.321658489 Reorder the terms: 7.5 + x = 8.321658489 Solving 7.5 + x = 8.321658489 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 = 8.321658489 + -7.5 Combine like terms: 7.5 + -7.5 = 0.0 0.0 + x = 8.321658489 + -7.5 x = 8.321658489 + -7.5 Combine like terms: 8.321658489 + -7.5 = 0.821658489 x = 0.821658489 Simplifying x = 0.821658489

Subproblem 2

x + 7.5 = -8.321658489 Simplifying x + 7.5 = -8.321658489 Reorder the terms: 7.5 + x = -8.321658489 Solving 7.5 + x = -8.321658489 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 = -8.321658489 + -7.5 Combine like terms: 7.5 + -7.5 = 0.0 0.0 + x = -8.321658489 + -7.5 x = -8.321658489 + -7.5 Combine like terms: -8.321658489 + -7.5 = -15.821658489 x = -15.821658489 Simplifying x = -15.821658489

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.821658489, -15.821658489}

See similar equations:

| 2x+9-8(x+1)=3x+6 | | -5m+12=m | | -0.25t^2+9t+26=0 | | -2(3x-2)=6 | | x^2-71x=0 | | 8=7-9x | | 96+x=180 | | (2x(2)-5x+3)-(-x(2)+4x-5)= | | (n+18)+(2n)=90 | | -2x-3x=-3 | | 6x-23=4x+11 | | 4(8-a)-42=16a-5(2+4a) | | 125+x=109+4*x | | 5+0.7x=9 | | 6x^2y+7xy^2=4 | | n-(31/3+22/3-11/3)=72/3 | | x(4x-4)+x(3x-2)=(7x+9)(x-2) | | 2x+90=360 | | -2x+3-x-4=-3(x+4)+2 | | 3x^2-11x+24=0 | | 6(x-2)-9=-3(-6x+9)-2x | | 5(3-2y)+4y=8 | | Xy-3a=5ax | | Y=-cos(3.14)x | | -1.6x+5=7.4 | | 3(2x+3)+97=110-5x | | 25+x=5-4*x | | 2(u+4)-3(6+u)=-2(u-7) | | (-3,-2),(5,4)= | | s=-16t^2+128t | | -8-2x=32 | | 2x+212=360 |

Equations solver categories