8x^2+15x-7=0

Simple and best practice solution for 8x^2+15x-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 8x^2+15x-7=0 equation:


Simplifying
8x2 + 15x + -7 = 0

Reorder the terms:
-7 + 15x + 8x2 = 0

Solving
-7 + 15x + 8x2 = 0

Solving for variable 'x'.

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

Divide each side by '8'.
-0.875 + 1.875x + x2 = 0

Move the constant term to the right:

Add '0.875' to each side of the equation.
-0.875 + 1.875x + 0.875 + x2 = 0 + 0.875

Reorder the terms:
-0.875 + 0.875 + 1.875x + x2 = 0 + 0.875

Combine like terms: -0.875 + 0.875 = 0.000
0.000 + 1.875x + x2 = 0 + 0.875
1.875x + x2 = 0 + 0.875

Combine like terms: 0 + 0.875 = 0.875
1.875x + x2 = 0.875

The x term is 1.875x.  Take half its coefficient (0.9375).
Square it (0.87890625) and add it to both sides.

Add '0.87890625' to each side of the equation.
1.875x + 0.87890625 + x2 = 0.875 + 0.87890625

Reorder the terms:
0.87890625 + 1.875x + x2 = 0.875 + 0.87890625

Combine like terms: 0.875 + 0.87890625 = 1.75390625
0.87890625 + 1.875x + x2 = 1.75390625

Factor a perfect square on the left side:
(x + 0.9375)(x + 0.9375) = 1.75390625

Calculate the square root of the right side: 1.324351256

Break this problem into two subproblems by setting 
(x + 0.9375) equal to 1.324351256 and -1.324351256.

Subproblem 1

x + 0.9375 = 1.324351256 Simplifying x + 0.9375 = 1.324351256 Reorder the terms: 0.9375 + x = 1.324351256 Solving 0.9375 + x = 1.324351256 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.9375' to each side of the equation. 0.9375 + -0.9375 + x = 1.324351256 + -0.9375 Combine like terms: 0.9375 + -0.9375 = 0.0000 0.0000 + x = 1.324351256 + -0.9375 x = 1.324351256 + -0.9375 Combine like terms: 1.324351256 + -0.9375 = 0.386851256 x = 0.386851256 Simplifying x = 0.386851256

Subproblem 2

x + 0.9375 = -1.324351256 Simplifying x + 0.9375 = -1.324351256 Reorder the terms: 0.9375 + x = -1.324351256 Solving 0.9375 + x = -1.324351256 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.9375' to each side of the equation. 0.9375 + -0.9375 + x = -1.324351256 + -0.9375 Combine like terms: 0.9375 + -0.9375 = 0.0000 0.0000 + x = -1.324351256 + -0.9375 x = -1.324351256 + -0.9375 Combine like terms: -1.324351256 + -0.9375 = -2.261851256 x = -2.261851256 Simplifying x = -2.261851256

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.386851256, -2.261851256}

See similar equations:

| 8.1+3.8h-5h=7.2 | | 9(-4x-3)-2y=8 | | 6m-3m+4=3-m+20 | | 3-x-8+4x=17 | | 10s^2-23s+12=0 | | (11x+7)-(6x-3)= | | 7(x+3)+3=7x-7 | | -p-13=3(5+4p)-2 | | -2x+55=8x+35 | | 3(2x+1)=2(-3x-1) | | 10x+9=15x-6 | | -2[x-3]=3 | | 14-D=9 | | 13.49+0.09x=1424-0.07x | | 2x^2-24x+82=0 | | 60.25=6.50+8.25x | | (5x+10)+(6x-4)=180 | | 4x+12=-58 | | 2b^4-6b^2-56=0 | | 5x-3=10x-20 | | 22x+10=98 | | 6z+22=76 | | 5+3x-8*(x-8)=180 | | 98=-3x+2 | | -5x-4=9x+3x-x | | r/5-8=3 | | 8x+5x=5x-6x+20 | | g(x)=4f(x)-5 | | -6-3+(2k+12)=18 | | 4d^2+28d-240=0 | | 41=3x-10 | | 4y^2+50y-150=0 |

Equations solver categories