x(x+1)=15

Simple and best practice solution for x(x+1)=15 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(x+1)=15 equation:


Simplifying
x(x + 1) = 15

Reorder the terms:
x(1 + x) = 15
(1 * x + x * x) = 15
(1x + x2) = 15

Solving
1x + x2 = 15

Solving for variable 'x'.

Reorder the terms:
-15 + 1x + x2 = 15 + -15

Combine like terms: 15 + -15 = 0
-15 + 1x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '15' to each side of the equation.
-15 + 1x + 15 + x2 = 0 + 15

Reorder the terms:
-15 + 15 + 1x + x2 = 0 + 15

Combine like terms: -15 + 15 = 0
0 + 1x + x2 = 0 + 15
1x + x2 = 0 + 15

Combine like terms: 0 + 15 = 15
1x + x2 = 15

The x term is 1x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
x + 0.25 + x2 = 15 + 0.25

Reorder the terms:
0.25 + x + x2 = 15 + 0.25

Combine like terms: 15 + 0.25 = 15.25
0.25 + x + x2 = 15.25

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = 15.25

Calculate the square root of the right side: 3.905124838

Break this problem into two subproblems by setting 
(x + 0.5) equal to 3.905124838 and -3.905124838.

Subproblem 1

x + 0.5 = 3.905124838 Simplifying x + 0.5 = 3.905124838 Reorder the terms: 0.5 + x = 3.905124838 Solving 0.5 + x = 3.905124838 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = 3.905124838 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = 3.905124838 + -0.5 x = 3.905124838 + -0.5 Combine like terms: 3.905124838 + -0.5 = 3.405124838 x = 3.405124838 Simplifying x = 3.405124838

Subproblem 2

x + 0.5 = -3.905124838 Simplifying x + 0.5 = -3.905124838 Reorder the terms: 0.5 + x = -3.905124838 Solving 0.5 + x = -3.905124838 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = -3.905124838 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = -3.905124838 + -0.5 x = -3.905124838 + -0.5 Combine like terms: -3.905124838 + -0.5 = -4.405124838 x = -4.405124838 Simplifying x = -4.405124838

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.405124838, -4.405124838}

See similar equations:

| 21x-12=16x+51 | | (X+6)=(4x-27) | | 188t-16t^2=92 | | 1.9a-0.9a-1.5=-1.5 | | 0=-4.9t^2+24.5t+2 | | 0.4x+2x=1.25 | | 68-v=176 | | 8z-7z=-9+7 | | 12(x)=32+8(x+1) | | 4.8=0.4x+2 | | 1+7t-5t^2=2 | | 1+7t-5t^2=0 | | 6y=5x+1 | | 11=8-3(x+3) | | 5x+18=7x | | x+203=154 | | 5y-4+y+41=7Y+40-4y | | 11u-4u=21 | | 44-6t-5t^2=0 | | 10.3z-9.3z-5.4=5.5-1.4 | | 1/9= | | -3-8f=-9f | | 5(-3+2x)=5x | | 14(n+2)=42 | | 5+ln(x-5)=4 | | (2x+25)=(3x-15) | | 43/6= | | 6x-2+10=55 | | .5x=-11 | | 156t-16t^2=60 | | 22n-21n-14=-21 | | 2x+24=3(2x+1) |

Equations solver categories