u^2+8u-15=0

Simple and best practice solution for u^2+8u-15=0 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 u^2+8u-15=0 equation:


Simplifying
u2 + 8u + -15 = 0

Reorder the terms:
-15 + 8u + u2 = 0

Solving
-15 + 8u + u2 = 0

Solving for variable 'u'.

Begin completing the square.

Move the constant term to the right:

Add '15' to each side of the equation.
-15 + 8u + 15 + u2 = 0 + 15

Reorder the terms:
-15 + 15 + 8u + u2 = 0 + 15

Combine like terms: -15 + 15 = 0
0 + 8u + u2 = 0 + 15
8u + u2 = 0 + 15

Combine like terms: 0 + 15 = 15
8u + u2 = 15

The u term is 8u.  Take half its coefficient (4).
Square it (16) and add it to both sides.

Add '16' to each side of the equation.
8u + 16 + u2 = 15 + 16

Reorder the terms:
16 + 8u + u2 = 15 + 16

Combine like terms: 15 + 16 = 31
16 + 8u + u2 = 31

Factor a perfect square on the left side:
(u + 4)(u + 4) = 31

Calculate the square root of the right side: 5.567764363

Break this problem into two subproblems by setting 
(u + 4) equal to 5.567764363 and -5.567764363.

Subproblem 1

u + 4 = 5.567764363 Simplifying u + 4 = 5.567764363 Reorder the terms: 4 + u = 5.567764363 Solving 4 + u = 5.567764363 Solving for variable 'u'. Move all terms containing u to the left, all other terms to the right. Add '-4' to each side of the equation. 4 + -4 + u = 5.567764363 + -4 Combine like terms: 4 + -4 = 0 0 + u = 5.567764363 + -4 u = 5.567764363 + -4 Combine like terms: 5.567764363 + -4 = 1.567764363 u = 1.567764363 Simplifying u = 1.567764363

Subproblem 2

u + 4 = -5.567764363 Simplifying u + 4 = -5.567764363 Reorder the terms: 4 + u = -5.567764363 Solving 4 + u = -5.567764363 Solving for variable 'u'. Move all terms containing u to the left, all other terms to the right. Add '-4' to each side of the equation. 4 + -4 + u = -5.567764363 + -4 Combine like terms: 4 + -4 = 0 0 + u = -5.567764363 + -4 u = -5.567764363 + -4 Combine like terms: -5.567764363 + -4 = -9.567764363 u = -9.567764363 Simplifying u = -9.567764363

Solution

The solution to the problem is based on the solutions from the subproblems. u = {1.567764363, -9.567764363}

See similar equations:

| 12x^2+39x+30= | | 5x^2+15x=40 | | 10x^3-34x^2+12x=0 | | x-7=2/3x | | -124-7x-2x=65 | | 4x^3-26x^2+30x=0 | | Z=14+y | | Ln(x/0,105)=-2,0232 | | (35x-10)+(35x)=0 | | 2/c=9-7 | | 14s^2+39s+10=0 | | 0=3y-7x-6 | | 14s^2+29s+10=0 | | 7-5y=3y-16 | | 34.20=2x-2.4 | | -7g+3=0 | | y=20-2.4 | | 9(y^2)-5y-4=0 | | x+x-7+x+40=180 | | 9n^2-9n-1=0 | | -8u^2+9u=0 | | 100+22x=70+75x | | x^2-3x-2=-x | | (x-7)2-(1+x)2=2(3x-4) | | 48000/746= | | 9b-3=190-4 | | 8k^2+6k-9=0 | | 200*240= | | 3d^2+9d+4=0 | | 6v^2-4=0 | | (17-s)/4=-11 | | 4w^2-7w+1=0 |

Equations solver categories