5x^2-8x-5=15

Simple and best practice solution for 5x^2-8x-5=15 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^2-8x-5=15 equation:


Simplifying
5x2 + -8x + -5 = 15

Reorder the terms:
-5 + -8x + 5x2 = 15

Solving
-5 + -8x + 5x2 = 15

Solving for variable 'x'.

Reorder the terms:
-5 + -15 + -8x + 5x2 = 15 + -15

Combine like terms: -5 + -15 = -20
-20 + -8x + 5x2 = 15 + -15

Combine like terms: 15 + -15 = 0
-20 + -8x + 5x2 = 0

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

Divide each side by '5'.
-4 + -1.6x + x2 = 0

Move the constant term to the right:

Add '4' to each side of the equation.
-4 + -1.6x + 4 + x2 = 0 + 4

Reorder the terms:
-4 + 4 + -1.6x + x2 = 0 + 4

Combine like terms: -4 + 4 = 0
0 + -1.6x + x2 = 0 + 4
-1.6x + x2 = 0 + 4

Combine like terms: 0 + 4 = 4
-1.6x + x2 = 4

The x term is -1.6x.  Take half its coefficient (-0.8).
Square it (0.64) and add it to both sides.

Add '0.64' to each side of the equation.
-1.6x + 0.64 + x2 = 4 + 0.64

Reorder the terms:
0.64 + -1.6x + x2 = 4 + 0.64

Combine like terms: 4 + 0.64 = 4.64
0.64 + -1.6x + x2 = 4.64

Factor a perfect square on the left side:
(x + -0.8)(x + -0.8) = 4.64

Calculate the square root of the right side: 2.154065923

Break this problem into two subproblems by setting 
(x + -0.8) equal to 2.154065923 and -2.154065923.

Subproblem 1

x + -0.8 = 2.154065923 Simplifying x + -0.8 = 2.154065923 Reorder the terms: -0.8 + x = 2.154065923 Solving -0.8 + x = 2.154065923 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.8' to each side of the equation. -0.8 + 0.8 + x = 2.154065923 + 0.8 Combine like terms: -0.8 + 0.8 = 0.0 0.0 + x = 2.154065923 + 0.8 x = 2.154065923 + 0.8 Combine like terms: 2.154065923 + 0.8 = 2.954065923 x = 2.954065923 Simplifying x = 2.954065923

Subproblem 2

x + -0.8 = -2.154065923 Simplifying x + -0.8 = -2.154065923 Reorder the terms: -0.8 + x = -2.154065923 Solving -0.8 + x = -2.154065923 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.8' to each side of the equation. -0.8 + 0.8 + x = -2.154065923 + 0.8 Combine like terms: -0.8 + 0.8 = 0.0 0.0 + x = -2.154065923 + 0.8 x = -2.154065923 + 0.8 Combine like terms: -2.154065923 + 0.8 = -1.354065923 x = -1.354065923 Simplifying x = -1.354065923

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.954065923, -1.354065923}

See similar equations:

| y(y-7)=49 | | x+5x+5x+4=99 | | 3*3*10-8= | | X(2x-7)=4(x-3) | | log1/2(x)=1 | | (3y+5)dx+(7x+2)dy=0 | | 3x(3-x)=14 | | 3x+2y+sqrt(4x-y)=5+sqrt(3) | | 6x-4n^2=0 | | 2x(9-5x)=-5x(2-3x) | | -49x^2=56 | | 1/5(x-8)x-16 | | 0.8x^2-4x-600=0 | | 6x^2-3x=2x+1 | | 6x+14=-14-10x | | 15x+8+2x+2=180 | | 6r=42 | | 5x-3=-2x-24 | | 0=8-9x^2+13x | | (-8.6)(0.04)= | | 12=4x+16 | | 7(2p+4)= | | (k+3)-(5k-3)=(3k-11)-(k+3) | | -5x+2x-3=17 | | 4x^2+x-1.5=0 | | 2a+2c=180 | | 7x^2-3x+8=9x^2+15 | | 180=4x+(2x-10)+(x+12) | | (k+3)-(5k-3)=(5k-3)-(3k-11) | | 4X^2+27X-45=0 | | (k+3)-(5k-3)=(3k-11)-(5k-3) | | 7x^2-2x-21=0 |

Equations solver categories