3x^3+20x^2+21x=0

Simple and best practice solution for 3x^3+20x^2+21x=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 3x^3+20x^2+21x=0 equation:


Simplifying
3x3 + 20x2 + 21x = 0

Reorder the terms:
21x + 20x2 + 3x3 = 0

Solving
21x + 20x2 + 3x3 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), 'x'.
x(21 + 20x + 3x2) = 0

Subproblem 1

Set the factor 'x' equal to zero and attempt to solve: Simplifying x = 0 Solving x = 0 Move all terms containing x to the left, all other terms to the right. Simplifying x = 0

Subproblem 2

Set the factor '(21 + 20x + 3x2)' equal to zero and attempt to solve: Simplifying 21 + 20x + 3x2 = 0 Solving 21 + 20x + 3x2 = 0 Begin completing the square. Divide all terms by 3 the coefficient of the squared term: Divide each side by '3'. 7 + 6.666666667x + x2 = 0 Move the constant term to the right: Add '-7' to each side of the equation. 7 + 6.666666667x + -7 + x2 = 0 + -7 Reorder the terms: 7 + -7 + 6.666666667x + x2 = 0 + -7 Combine like terms: 7 + -7 = 0 0 + 6.666666667x + x2 = 0 + -7 6.666666667x + x2 = 0 + -7 Combine like terms: 0 + -7 = -7 6.666666667x + x2 = -7 The x term is 6.666666667x. Take half its coefficient (3.333333334). Square it (11.11111112) and add it to both sides. Add '11.11111112' to each side of the equation. 6.666666667x + 11.11111112 + x2 = -7 + 11.11111112 Reorder the terms: 11.11111112 + 6.666666667x + x2 = -7 + 11.11111112 Combine like terms: -7 + 11.11111112 = 4.11111112 11.11111112 + 6.666666667x + x2 = 4.11111112 Factor a perfect square on the left side: (x + 3.333333334)(x + 3.333333334) = 4.11111112 Calculate the square root of the right side: 2.027587512 Break this problem into two subproblems by setting (x + 3.333333334) equal to 2.027587512 and -2.027587512.

Subproblem 1

x + 3.333333334 = 2.027587512 Simplifying x + 3.333333334 = 2.027587512 Reorder the terms: 3.333333334 + x = 2.027587512 Solving 3.333333334 + x = 2.027587512 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-3.333333334' to each side of the equation. 3.333333334 + -3.333333334 + x = 2.027587512 + -3.333333334 Combine like terms: 3.333333334 + -3.333333334 = 0.000000000 0.000000000 + x = 2.027587512 + -3.333333334 x = 2.027587512 + -3.333333334 Combine like terms: 2.027587512 + -3.333333334 = -1.305745822 x = -1.305745822 Simplifying x = -1.305745822

Subproblem 2

x + 3.333333334 = -2.027587512 Simplifying x + 3.333333334 = -2.027587512 Reorder the terms: 3.333333334 + x = -2.027587512 Solving 3.333333334 + x = -2.027587512 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-3.333333334' to each side of the equation. 3.333333334 + -3.333333334 + x = -2.027587512 + -3.333333334 Combine like terms: 3.333333334 + -3.333333334 = 0.000000000 0.000000000 + x = -2.027587512 + -3.333333334 x = -2.027587512 + -3.333333334 Combine like terms: -2.027587512 + -3.333333334 = -5.360920846 x = -5.360920846 Simplifying x = -5.360920846

Solution

The solution to the problem is based on the solutions from the subproblems. x = {-1.305745822, -5.360920846}

Solution

x = {0, -1.305745822, -5.360920846}

See similar equations:

| 75.4=2pi | | 8w-(4w-6)=14 | | N+2n=27 | | 44-40x=9x+18 | | r^2-6r-18=0 | | -2(-1)+(3-1+1)-3(6+-1)=-1 | | 9+(5+y)= | | 5n+2-8=2n | | 2(6y-5)=26 | | -23=-2(13)-10+13 | | (t-8)(t-3)=2 | | 8.1(x+8.9)=86.67 | | -11x+101=-5x-49 | | -2-1+(3-1+1)-3(6+-1)=-1 | | 8w+12=4w-18 | | -2(p-3)= | | 6(x-4)+3=9x+3 | | 30=5(6n+2) | | 160=4*6*5+2*5*h | | g-18=-6 | | 1+2x=3+3x | | 5y-90=-135 | | 9+5x=-12+2x | | 7b-(2b-7)= | | 39.99+.45m=44.99+.40m | | 17r-12r-2r-2r=15 | | Y=a+(x-1)w | | 35+0.8x=75 | | 21=-8x+2x+1 | | 4y-3y+3y-4y+2y=20 | | 5x=11x+84 | | 384=-8(1+7n) |

Equations solver categories