3b^2-4b-72=0

Simple and best practice solution for 3b^2-4b-72=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 3b^2-4b-72=0 equation:


Simplifying
3b2 + -4b + -72 = 0

Reorder the terms:
-72 + -4b + 3b2 = 0

Solving
-72 + -4b + 3b2 = 0

Solving for variable 'b'.

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

Divide each side by '3'.
-24 + -1.333333333b + b2 = 0

Move the constant term to the right:

Add '24' to each side of the equation.
-24 + -1.333333333b + 24 + b2 = 0 + 24

Reorder the terms:
-24 + 24 + -1.333333333b + b2 = 0 + 24

Combine like terms: -24 + 24 = 0
0 + -1.333333333b + b2 = 0 + 24
-1.333333333b + b2 = 0 + 24

Combine like terms: 0 + 24 = 24
-1.333333333b + b2 = 24

The b term is -1.333333333b.  Take half its coefficient (-0.6666666665).
Square it (0.4444444442) and add it to both sides.

Add '0.4444444442' to each side of the equation.
-1.333333333b + 0.4444444442 + b2 = 24 + 0.4444444442

Reorder the terms:
0.4444444442 + -1.333333333b + b2 = 24 + 0.4444444442

Combine like terms: 24 + 0.4444444442 = 24.4444444442
0.4444444442 + -1.333333333b + b2 = 24.4444444442

Factor a perfect square on the left side:
(b + -0.6666666665)(b + -0.6666666665) = 24.4444444442

Calculate the square root of the right side: 4.944132325

Break this problem into two subproblems by setting 
(b + -0.6666666665) equal to 4.944132325 and -4.944132325.

Subproblem 1

b + -0.6666666665 = 4.944132325 Simplifying b + -0.6666666665 = 4.944132325 Reorder the terms: -0.6666666665 + b = 4.944132325 Solving -0.6666666665 + b = 4.944132325 Solving for variable 'b'. Move all terms containing b to the left, all other terms to the right. Add '0.6666666665' to each side of the equation. -0.6666666665 + 0.6666666665 + b = 4.944132325 + 0.6666666665 Combine like terms: -0.6666666665 + 0.6666666665 = 0.0000000000 0.0000000000 + b = 4.944132325 + 0.6666666665 b = 4.944132325 + 0.6666666665 Combine like terms: 4.944132325 + 0.6666666665 = 5.6107989915 b = 5.6107989915 Simplifying b = 5.6107989915

Subproblem 2

b + -0.6666666665 = -4.944132325 Simplifying b + -0.6666666665 = -4.944132325 Reorder the terms: -0.6666666665 + b = -4.944132325 Solving -0.6666666665 + b = -4.944132325 Solving for variable 'b'. Move all terms containing b to the left, all other terms to the right. Add '0.6666666665' to each side of the equation. -0.6666666665 + 0.6666666665 + b = -4.944132325 + 0.6666666665 Combine like terms: -0.6666666665 + 0.6666666665 = 0.0000000000 0.0000000000 + b = -4.944132325 + 0.6666666665 b = -4.944132325 + 0.6666666665 Combine like terms: -4.944132325 + 0.6666666665 = -4.2774656585 b = -4.2774656585 Simplifying b = -4.2774656585

Solution

The solution to the problem is based on the solutions from the subproblems. b = {5.6107989915, -4.2774656585}

See similar equations:

| 18=x-y | | 0.2z=-32 | | 7(x+1)+7(x+1)=6x-6 | | 5b-20= | | 3X+2X=106 | | 6n+8=n | | 9k-7=k+9 | | .6666666667n=10 | | 2b+11=14 | | 10(8x-6)= | | 7a-6=a^2+4 | | x*x-7=2(x+x-7) | | 6x+26=3x+101 | | 13s=2s-56 | | 6x-3+5x=12 | | x*(x-7)=2(x+x-7) | | (r^4)+64=0 | | 10n-2=-8+9n | | 3y+1=2 | | (36x^2)+24x=0 | | y+16=3y-34 | | 3x-13=7x+11 | | -7x+3=13x-37 | | 6x=y+3 | | 8v-8=3v | | x+1=3(2x+8) | | 2(3x-2)=2(17x+18) | | 3u-8=31 | | 3u-8=11 | | 25=2v+11 | | W+11w+9w-18w-4w-3=2 | | =2d+3.2 |

Equations solver categories