4=0.3x^2-x-8

Simple and best practice solution for 4=0.3x^2-x-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 4=0.3x^2-x-8 equation:


Simplifying
4 = 0.3x2 + -1x + -8

Reorder the terms:
4 = -8 + -1x + 0.3x2

Solving
4 = -8 + -1x + 0.3x2

Solving for variable 'x'.

Combine like terms: 4 + 8 = 12
12 + x + -0.3x2 = -8 + -1x + 0.3x2 + 8 + x + -0.3x2

Reorder the terms:
12 + x + -0.3x2 = -8 + 8 + -1x + x + 0.3x2 + -0.3x2

Combine like terms: -8 + 8 = 0
12 + x + -0.3x2 = 0 + -1x + x + 0.3x2 + -0.3x2
12 + x + -0.3x2 = -1x + x + 0.3x2 + -0.3x2

Combine like terms: -1x + x = 0
12 + x + -0.3x2 = 0 + 0.3x2 + -0.3x2
12 + x + -0.3x2 = 0.3x2 + -0.3x2

Combine like terms: 0.3x2 + -0.3x2 = 0.0
12 + x + -0.3x2 = 0.0

Begin completing the square.  Divide all terms by
-0.3 the coefficient of the squared term: 

Divide each side by '-0.3'.
-40 + -3.333333333x + x2 = 0

Move the constant term to the right:

Add '40' to each side of the equation.
-40 + -3.333333333x + 40 + x2 = 0 + 40

Reorder the terms:
-40 + 40 + -3.333333333x + x2 = 0 + 40

Combine like terms: -40 + 40 = 0
0 + -3.333333333x + x2 = 0 + 40
-3.333333333x + x2 = 0 + 40

Combine like terms: 0 + 40 = 40
-3.333333333x + x2 = 40

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-3.333333333x + 0.25 + x2 = 40 + 0.25

Reorder the terms:
0.25 + -3.333333333x + x2 = 40 + 0.25

Combine like terms: 40 + 0.25 = 40.25
0.25 + -3.333333333x + x2 = 40.25

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = 40.25

Calculate the square root of the right side: 6.34428877

Break this problem into two subproblems by setting 
(x + 0.5) equal to 6.34428877 and -6.34428877.

Subproblem 1

x + 0.5 = 6.34428877 Simplifying x + 0.5 = 6.34428877 Reorder the terms: 0.5 + x = 6.34428877 Solving 0.5 + x = 6.34428877 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = 6.34428877 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = 6.34428877 + -0.5 x = 6.34428877 + -0.5 Combine like terms: 6.34428877 + -0.5 = 5.84428877 x = 5.84428877 Simplifying x = 5.84428877

Subproblem 2

x + 0.5 = -6.34428877 Simplifying x + 0.5 = -6.34428877 Reorder the terms: 0.5 + x = -6.34428877 Solving 0.5 + x = -6.34428877 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = -6.34428877 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = -6.34428877 + -0.5 x = -6.34428877 + -0.5 Combine like terms: -6.34428877 + -0.5 = -6.84428877 x = -6.84428877 Simplifying x = -6.84428877

Solution

The solution to the problem is based on the solutions from the subproblems. x = {5.84428877, -6.84428877}

See similar equations:

| 2x^2+x=1 | | 0.7x+2(x-3)=0.2+3 | | z=11+4x+4y | | 2x+9=6x+3 | | 2x-9=6x+3 | | (x+5)(x-3)= | | -3(4n+6)=3 | | 15x^5-30x^3=0 | | 2(x-2)=3x-2-x | | 5x^2-18x+17=0 | | 2x-1=10x+5 | | 2(x-8)=3(x+8) | | 3x-(5x+3)=10-2x | | 2x-1=10+5 | | 2(x-8)=3x+8 | | 9.6=6y | | -1+2x=5+10X | | -6x+7(2x+1)-12= | | 3x^3y^2-27x^2y=0 | | 2w^2+6w+8=0 | | (-2x^2+10x-8)(x^2-4)=0 | | 5(2z-1)-3(z+9)=3(z+1) | | 12x^2+16x-3=0 | | 20-5(2n-4)=4(n+1)-6 | | 9w^2-6w+1=0 | | x^2+15x+56.25=0 | | 7(3+c)=6(c-1) | | -6+8x=4+4x | | 5+2(5x-4)=5-3(2x+1) | | 2(2c-1)-6=2c+2 | | (x+4)(x+9)= | | 3x^2+13x+10=0 |

Equations solver categories