3x^2+15x+8=

Simple and best practice solution for 3x^2+15x+8= 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+15x+8= equation:


Simplifying
3x2 + 15x + 8 = 0

Reorder the terms:
8 + 15x + 3x2 = 0

Solving
8 + 15x + 3x2 = 0

Solving for variable 'x'.

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

Divide each side by '3'.
2.666666667 + 5x + x2 = 0

Move the constant term to the right:

Add '-2.666666667' to each side of the equation.
2.666666667 + 5x + -2.666666667 + x2 = 0 + -2.666666667

Reorder the terms:
2.666666667 + -2.666666667 + 5x + x2 = 0 + -2.666666667

Combine like terms: 2.666666667 + -2.666666667 = 0.000000000
0.000000000 + 5x + x2 = 0 + -2.666666667
5x + x2 = 0 + -2.666666667

Combine like terms: 0 + -2.666666667 = -2.666666667
5x + x2 = -2.666666667

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 = -2.666666667 + 6.25

Reorder the terms:
6.25 + 5x + x2 = -2.666666667 + 6.25

Combine like terms: -2.666666667 + 6.25 = 3.583333333
6.25 + 5x + x2 = 3.583333333

Factor a perfect square on the left side:
(x + 2.5)(x + 2.5) = 3.583333333

Calculate the square root of the right side: 1.892969449

Break this problem into two subproblems by setting 
(x + 2.5) equal to 1.892969449 and -1.892969449.

Subproblem 1

x + 2.5 = 1.892969449 Simplifying x + 2.5 = 1.892969449 Reorder the terms: 2.5 + x = 1.892969449 Solving 2.5 + x = 1.892969449 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 = 1.892969449 + -2.5 Combine like terms: 2.5 + -2.5 = 0.0 0.0 + x = 1.892969449 + -2.5 x = 1.892969449 + -2.5 Combine like terms: 1.892969449 + -2.5 = -0.607030551 x = -0.607030551 Simplifying x = -0.607030551

Subproblem 2

x + 2.5 = -1.892969449 Simplifying x + 2.5 = -1.892969449 Reorder the terms: 2.5 + x = -1.892969449 Solving 2.5 + x = -1.892969449 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 = -1.892969449 + -2.5 Combine like terms: 2.5 + -2.5 = 0.0 0.0 + x = -1.892969449 + -2.5 x = -1.892969449 + -2.5 Combine like terms: -1.892969449 + -2.5 = -4.392969449 x = -4.392969449 Simplifying x = -4.392969449

Solution

The solution to the problem is based on the solutions from the subproblems. x = {-0.607030551, -4.392969449}

See similar equations:

| 19x-37x= | | .06x+x=33310 | | -3(8p+5)-2(1-20p)=3(6+5p) | | 7n-34=-3-6(5n-1) | | 3(x+30)+x(42)+195=390 | | 12(m-3)-1=-(5m+9) | | 4(x-12)=16x | | -9x+14x= | | r=wp | | 2m-2x=x+p | | .02x+x=14280 | | 16x-3x=13x | | 6(1+4b)=-6(4b-4) | | .25z-.75=-.25x+3.25 | | 5y+38+3x=180 | | -9(v+2)+3v+7=6v+8 | | 3w+5k-4w+k= | | 5x^2-7x+37=0 | | 26x+18=5(5x+2) | | -3(3x+7)-5x=29-4x | | 36x^2+25= | | .25z-.75=-.25+3.25 | | 2y=30-8x | | -4n(n-1)=6.5 | | y=1/5+3 | | 5x-6x+9=4x-1 | | 8(r+7)+5r=-5(6+6r) | | -14=s+12/6 | | 6m+7-2m+1= | | 418=-122a | | x+(2x-8)+(3x-12)=82 | | 8+-(5t+2)=16 |

Equations solver categories