-x^2+12x+15=0

Simple and best practice solution for -x^2+12x+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 -x^2+12x+15=0 equation:


Simplifying
-1x2 + 12x + 15 = 0

Reorder the terms:
15 + 12x + -1x2 = 0

Solving
15 + 12x + -1x2 = 0

Solving for variable 'x'.

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

Divide each side by '-1'.
-15 + -12x + x2 = 0

Move the constant term to the right:

Add '15' to each side of the equation.
-15 + -12x + 15 + x2 = 0 + 15

Reorder the terms:
-15 + 15 + -12x + x2 = 0 + 15

Combine like terms: -15 + 15 = 0
0 + -12x + x2 = 0 + 15
-12x + x2 = 0 + 15

Combine like terms: 0 + 15 = 15
-12x + x2 = 15

The x term is -12x.  Take half its coefficient (-6).
Square it (36) and add it to both sides.

Add '36' to each side of the equation.
-12x + 36 + x2 = 15 + 36

Reorder the terms:
36 + -12x + x2 = 15 + 36

Combine like terms: 15 + 36 = 51
36 + -12x + x2 = 51

Factor a perfect square on the left side:
(x + -6)(x + -6) = 51

Calculate the square root of the right side: 7.141428429

Break this problem into two subproblems by setting 
(x + -6) equal to 7.141428429 and -7.141428429.

Subproblem 1

x + -6 = 7.141428429 Simplifying x + -6 = 7.141428429 Reorder the terms: -6 + x = 7.141428429 Solving -6 + x = 7.141428429 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '6' to each side of the equation. -6 + 6 + x = 7.141428429 + 6 Combine like terms: -6 + 6 = 0 0 + x = 7.141428429 + 6 x = 7.141428429 + 6 Combine like terms: 7.141428429 + 6 = 13.141428429 x = 13.141428429 Simplifying x = 13.141428429

Subproblem 2

x + -6 = -7.141428429 Simplifying x + -6 = -7.141428429 Reorder the terms: -6 + x = -7.141428429 Solving -6 + x = -7.141428429 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '6' to each side of the equation. -6 + 6 + x = -7.141428429 + 6 Combine like terms: -6 + 6 = 0 0 + x = -7.141428429 + 6 x = -7.141428429 + 6 Combine like terms: -7.141428429 + 6 = -1.141428429 x = -1.141428429 Simplifying x = -1.141428429

Solution

The solution to the problem is based on the solutions from the subproblems. x = {13.141428429, -1.141428429}

See similar equations:

| -5-[(-9-5)+16]-17= | | x^2(x^2+1)-4(x^2+1)=0 | | -5[(-9-5)+16]-17= | | n=m-12 | | 3w+3=27+9w | | y+16=x | | -33+(7)=29+m | | 2(x-5)-3(3-x)=1/2(x-2) | | (5b+2g)(5b-2g)= | | x^2+5y=20 | | 6(3x+2)=500 | | 43/45-1/21 | | 14=ab | | 43/54-1/21 | | 7-8v=-5-4v | | 7-8v=-54v | | y-8=x | | 4x^2+40x+96= | | 5x-10y=7 | | 16=s+p | | 6(x-1)-3x=4x+6 | | 8y=-4x-4 | | -2x-4y=2 | | 5(2x+2)+3(4x+3)+3=22x+22 | | 9x^2+18x+5=0 | | 2+7y=16+2 | | an=5n+2 | | 5+2+3= | | s*9=p | | 2t^2-6t-3=0 | | t^2-6t-3=0 | | 2g+5=13+6g |

Equations solver categories