-3x(x-5)=15

Simple and best practice solution for -3x(x-5)=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 -3x(x-5)=15 equation: 


Simplifying
-3x(x + -5) = 15

Reorder the terms:
-3x(-5 + x) = 15
(-5 * -3x + x * -3x) = 15
(15x + -3x2) = 15

Solving
15x + -3x2 = 15

Solving for variable 'x'.

Reorder the terms:
-15 + 15x + -3x2 = 15 + -15

Combine like terms: 15 + -15 = 0
-15 + 15x + -3x2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(-5 + 5x + -1x2) = 0

Ignore the factor 3.

Subproblem 1
Set the factor '(-5 + 5x + -1x2)' equal to zero and attempt to solve:

Simplifying
-5 + 5x + -1x2 = 0

Solving
-5 + 5x + -1x2 = 0

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

Divide each side by '-1'.
5 + -5x + x2 = 0

Move the constant term to the right:

Add '-5' to each side of the equation.
5 + -5x + -5 + x2 = 0 + -5

Reorder the terms:
5 + -5 + -5x + x2 = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -5x + x2 = 0 + -5
-5x + x2 = 0 + -5

Combine like terms: 0 + -5 = -5
-5x + x2 = -5

The x term is -5x.  Take half its coefficient (-2.5).
Square it (6.25) and add it to both sides.

Add '6.25' to each side of the equation.
-5x + 6.25 + x2 = -5 + 6.25

Reorder the terms:
6.25 + -5x + x2 = -5 + 6.25

Combine like terms: -5 + 6.25 = 1.25
6.25 + -5x + x2 = 1.25

Factor a perfect square on the left side:
(x + -2.5)(x + -2.5) = 1.25

Calculate the square root of the right side: 1.118033989

Break this problem into two subproblems by setting 
(x + -2.5) equal to 1.118033989 and -1.118033989.


Subproblem 1
x + -2.5 = 1.118033989

Simplifying
x + -2.5 = 1.118033989

Reorder the terms:
-2.5 + x = 1.118033989

Solving
-2.5 + x = 1.118033989

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '2.5' to each side of the equation.
-2.5 + 2.5 + x = 1.118033989 + 2.5

Combine like terms: -2.5 + 2.5 = 0.0
0.0 + x = 1.118033989 + 2.5
x = 1.118033989 + 2.5

Combine like terms: 1.118033989 + 2.5 = 3.618033989
x = 3.618033989

Simplifying
x = 3.618033989


Subproblem 2
x + -2.5 = -1.118033989

Simplifying
x + -2.5 = -1.118033989

Reorder the terms:
-2.5 + x = -1.118033989

Solving
-2.5 + x = -1.118033989

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '2.5' to each side of the equation.
-2.5 + 2.5 + x = -1.118033989 + 2.5

Combine like terms: -2.5 + 2.5 = 0.0
0.0 + x = -1.118033989 + 2.5
x = -1.118033989 + 2.5

Combine like terms: -1.118033989 + 2.5 = 1.381966011
x = 1.381966011

Simplifying
x = 1.381966011


Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {3.618033989, 1.381966011}
Solution
x = {3.618033989, 1.381966011}

See similar equations:

| 3x+1.3=8.8 | | -(5x-2y-3z)= | | ((w^3)/(w^-12)(m^-15))^3 | | ((w^3)/(w^-12*m^-15))^3 | | x+(x*16.50)=5000 | | 1x+1y=6.10 | | -0.4375=(-0.25*-0.25)+x | | -(3/8)x-(8/5) | | -3/8x-8/5 | | 4-3x=-6x+1 | | (2x+1)(7x^2+8x+4)= | | (30+2y)(y)=100 | | B/2A=3 | | 3x-[-(-2)]x+(-3)(x+2)=5x+(-7) | | x^2+.000413x-.000541=0 | | x*0.07=80 | | (2X+7)(3X-6u-7)= | | 5.25*X=6.00 | | x+x+0.01+x+0.01+1.08=9.41 | | x+5x-15+4x=180 | | 5X(4X+5)= | | 4x-19.5x+5x-15=180 | | 0.2x+3=8.2 | | 1/8x-6=1 | | 19.5+4x+5x-15=180 | | 4x+5x-15= | | 6=x/5.9 | | 4x+5x-15=180 | | 2x-q=p | | 2x=3604 | | 3c-12=-6 | | 40x=4x+(32-4)*(x+10) |

Equations solver categories