2x^2-8x-7=0

Simple and best practice solution for 2x^2-8x-7=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 2x^2-8x-7=0 equation:


Simplifying
2x2 + -8x + -7 = 0

Reorder the terms:
-7 + -8x + 2x2 = 0

Solving
-7 + -8x + 2x2 = 0

Solving for variable 'x'.

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

Divide each side by '2'.
-3.5 + -4x + x2 = 0

Move the constant term to the right:

Add '3.5' to each side of the equation.
-3.5 + -4x + 3.5 + x2 = 0 + 3.5

Reorder the terms:
-3.5 + 3.5 + -4x + x2 = 0 + 3.5

Combine like terms: -3.5 + 3.5 = 0.0
0.0 + -4x + x2 = 0 + 3.5
-4x + x2 = 0 + 3.5

Combine like terms: 0 + 3.5 = 3.5
-4x + x2 = 3.5

The x term is -4x.  Take half its coefficient (-2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
-4x + 4 + x2 = 3.5 + 4

Reorder the terms:
4 + -4x + x2 = 3.5 + 4

Combine like terms: 3.5 + 4 = 7.5
4 + -4x + x2 = 7.5

Factor a perfect square on the left side:
(x + -2)(x + -2) = 7.5

Calculate the square root of the right side: 2.738612788

Break this problem into two subproblems by setting 
(x + -2) equal to 2.738612788 and -2.738612788.

Subproblem 1

x + -2 = 2.738612788 Simplifying x + -2 = 2.738612788 Reorder the terms: -2 + x = 2.738612788 Solving -2 + x = 2.738612788 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2' to each side of the equation. -2 + 2 + x = 2.738612788 + 2 Combine like terms: -2 + 2 = 0 0 + x = 2.738612788 + 2 x = 2.738612788 + 2 Combine like terms: 2.738612788 + 2 = 4.738612788 x = 4.738612788 Simplifying x = 4.738612788

Subproblem 2

x + -2 = -2.738612788 Simplifying x + -2 = -2.738612788 Reorder the terms: -2 + x = -2.738612788 Solving -2 + x = -2.738612788 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2' to each side of the equation. -2 + 2 + x = -2.738612788 + 2 Combine like terms: -2 + 2 = 0 0 + x = -2.738612788 + 2 x = -2.738612788 + 2 Combine like terms: -2.738612788 + 2 = -0.738612788 x = -0.738612788 Simplifying x = -0.738612788

Solution

The solution to the problem is based on the solutions from the subproblems. x = {4.738612788, -0.738612788}

See similar equations:

| x*.06=2725.18 | | x+(x*2)=10 | | 4x-3=12x-32 | | 0=t^2-50t+35 | | 10x+9=6x+33 | | 5x-19=41 | | t^2+50t-35=0 | | 11x-14=6x+16 | | 12x-7=6x-13 | | 6x+17=5x+12 | | 2x+1=-11 | | 5x+18=x+10 | | 76-4x=2x+10 | | 11x-8=4x-50 | | 6(2v-7)=-(v+1) | | 4x-8=2x+8 | | 2x-16=-6 | | x+10=-x+8 | | -x+1=-2x+3 | | y-12=2(y-7) | | 2x^2=x-2 | | 8(b-1)=2(b+2) | | 7(n-2)=n+4 | | 3-4r=5r+12 | | 4x^3+3x^2=10x | | 6x+4=5x-7 | | 2x^2+17x=42 | | x^3-4x^2+3x=0 | | -16t^2+64t=-3 | | 125x^4-x=0 | | 2x(3x-1)=140 | | 3x^2+4xy+y^2=0 |

Equations solver categories