5x^2-4x=8

Simple and best practice solution for 5x^2-4x=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 5x^2-4x=8 equation:


Simplifying
5x2 + -4x = 8

Reorder the terms:
-4x + 5x2 = 8

Solving
-4x + 5x2 = 8

Solving for variable 'x'.

Reorder the terms:
-8 + -4x + 5x2 = 8 + -8

Combine like terms: 8 + -8 = 0
-8 + -4x + 5x2 = 0

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

Divide each side by '5'.
-1.6 + -0.8x + x2 = 0

Move the constant term to the right:

Add '1.6' to each side of the equation.
-1.6 + -0.8x + 1.6 + x2 = 0 + 1.6

Reorder the terms:
-1.6 + 1.6 + -0.8x + x2 = 0 + 1.6

Combine like terms: -1.6 + 1.6 = 0.0
0.0 + -0.8x + x2 = 0 + 1.6
-0.8x + x2 = 0 + 1.6

Combine like terms: 0 + 1.6 = 1.6
-0.8x + x2 = 1.6

The x term is -0.8x.  Take half its coefficient (-0.4).
Square it (0.16) and add it to both sides.

Add '0.16' to each side of the equation.
-0.8x + 0.16 + x2 = 1.6 + 0.16

Reorder the terms:
0.16 + -0.8x + x2 = 1.6 + 0.16

Combine like terms: 1.6 + 0.16 = 1.76
0.16 + -0.8x + x2 = 1.76

Factor a perfect square on the left side:
(x + -0.4)(x + -0.4) = 1.76

Calculate the square root of the right side: 1.326649916

Break this problem into two subproblems by setting 
(x + -0.4) equal to 1.326649916 and -1.326649916.

Subproblem 1

x + -0.4 = 1.326649916 Simplifying x + -0.4 = 1.326649916 Reorder the terms: -0.4 + x = 1.326649916 Solving -0.4 + x = 1.326649916 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.4' to each side of the equation. -0.4 + 0.4 + x = 1.326649916 + 0.4 Combine like terms: -0.4 + 0.4 = 0.0 0.0 + x = 1.326649916 + 0.4 x = 1.326649916 + 0.4 Combine like terms: 1.326649916 + 0.4 = 1.726649916 x = 1.726649916 Simplifying x = 1.726649916

Subproblem 2

x + -0.4 = -1.326649916 Simplifying x + -0.4 = -1.326649916 Reorder the terms: -0.4 + x = -1.326649916 Solving -0.4 + x = -1.326649916 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.4' to each side of the equation. -0.4 + 0.4 + x = -1.326649916 + 0.4 Combine like terms: -0.4 + 0.4 = 0.0 0.0 + x = -1.326649916 + 0.4 x = -1.326649916 + 0.4 Combine like terms: -1.326649916 + 0.4 = -0.926649916 x = -0.926649916 Simplifying x = -0.926649916

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.726649916, -0.926649916}

See similar equations:

| 10-8=3b-1 | | 9k^2=24 | | 9x-61=129-x | | 16=x-2x+7 | | .5*15*h=30 | | 2x^2+3x^2=4x^2 | | 4x^2+32x-1=0 | | -52+8x=92-x | | (3-7m)+2(3.5+1)= | | 3(-2x+3)=-33 | | -91+6x=69-2x | | 7b-8=3b | | 5(10x-3)=7 | | a+a+10+a+15=225 | | 5c-4c=6c-2 | | -3x-96=-10x+30 | | 1x+16y= | | 12x-2x+5=85 | | 10x-81=x+72 | | -7(x+8)-3=-59 | | 2(4n)+4(8+y)= | | (3x+2)(5x-4)=0 | | 6x-94=46+x | | -6(2x+5)=90 | | -3x-109=53-9x | | 5=6(q-5) | | 2(1-2x)-x=3(x-1)+7 | | 7+1+7r-2r=r+1+5r | | 2(5+x)+3(4x+2y)= | | 4(3n+3)=8(5n+1)+1 | | 10x-4+7x+4=180 | | x+3x-40=48 |

Equations solver categories