3x^2-15=-11x

Simple and best practice solution for 3x^2-15=-11x 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^2-15=-11x equation:


Simplifying
3x2 + -15 = -11x

Reorder the terms:
-15 + 3x2 = -11x

Solving
-15 + 3x2 = -11x

Solving for variable 'x'.

Reorder the terms:
-15 + 11x + 3x2 = -11x + 11x

Combine like terms: -11x + 11x = 0
-15 + 11x + 3x2 = 0

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

Divide each side by '3'.
-5 + 3.666666667x + x2 = 0

Move the constant term to the right:

Add '5' to each side of the equation.
-5 + 3.666666667x + 5 + x2 = 0 + 5

Reorder the terms:
-5 + 5 + 3.666666667x + x2 = 0 + 5

Combine like terms: -5 + 5 = 0
0 + 3.666666667x + x2 = 0 + 5
3.666666667x + x2 = 0 + 5

Combine like terms: 0 + 5 = 5
3.666666667x + x2 = 5

The x term is 3.666666667x.  Take half its coefficient (1.833333334).
Square it (3.361111114) and add it to both sides.

Add '3.361111114' to each side of the equation.
3.666666667x + 3.361111114 + x2 = 5 + 3.361111114

Reorder the terms:
3.361111114 + 3.666666667x + x2 = 5 + 3.361111114

Combine like terms: 5 + 3.361111114 = 8.361111114
3.361111114 + 3.666666667x + x2 = 8.361111114

Factor a perfect square on the left side:
(x + 1.833333334)(x + 1.833333334) = 8.361111114

Calculate the square root of the right side: 2.891558596

Break this problem into two subproblems by setting 
(x + 1.833333334) equal to 2.891558596 and -2.891558596.

Subproblem 1

x + 1.833333334 = 2.891558596 Simplifying x + 1.833333334 = 2.891558596 Reorder the terms: 1.833333334 + x = 2.891558596 Solving 1.833333334 + x = 2.891558596 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.833333334' to each side of the equation. 1.833333334 + -1.833333334 + x = 2.891558596 + -1.833333334 Combine like terms: 1.833333334 + -1.833333334 = 0.000000000 0.000000000 + x = 2.891558596 + -1.833333334 x = 2.891558596 + -1.833333334 Combine like terms: 2.891558596 + -1.833333334 = 1.058225262 x = 1.058225262 Simplifying x = 1.058225262

Subproblem 2

x + 1.833333334 = -2.891558596 Simplifying x + 1.833333334 = -2.891558596 Reorder the terms: 1.833333334 + x = -2.891558596 Solving 1.833333334 + x = -2.891558596 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.833333334' to each side of the equation. 1.833333334 + -1.833333334 + x = -2.891558596 + -1.833333334 Combine like terms: 1.833333334 + -1.833333334 = 0.000000000 0.000000000 + x = -2.891558596 + -1.833333334 x = -2.891558596 + -1.833333334 Combine like terms: -2.891558596 + -1.833333334 = -4.72489193 x = -4.72489193 Simplifying x = -4.72489193

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.058225262, -4.72489193}

See similar equations:

| 3x^2=-9 | | x/10=6/8 | | 5n^2=-9 | | 8p^2-19=p | | 6n^2-7n=143 | | 3+4+5=151872 | | 0.848=-0.2(6.5N-2) | | 0.8409=-0.2(6.5N-2) | | 9n^2-11n=-4 | | X^2=-8x+105 | | 8-2d/5+11=21 | | 6a^2=-7a-6 | | 2j+6k=48 | | 5x-9/3=7 | | 5x^2+5=7x | | y+5/2=-7 | | m/4+7=13 | | 2j+2k=20 | | 5(4-2m)=16-8m | | 10/9=x/10*9 | | -(2k+7)=13 | | 2(r+6)=24 | | 10/9=5/90 | | 20-6p=4-2p | | 3g+2h=7 | | 13k-18=4k | | 3m=m+12 | | -9=5-2y | | 6-4c=26 | | m/7+15=13 | | m/7+15 | | 4g+2h=8 |

Equations solver categories