18x^2+8x-1=0

Simple and best practice solution for 18x^2+8x-1=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 18x^2+8x-1=0 equation:


Simplifying
18x2 + 8x + -1 = 0

Reorder the terms:
-1 + 8x + 18x2 = 0

Solving
-1 + 8x + 18x2 = 0

Solving for variable 'x'.

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

Divide each side by '18'.
-0.05555555556 + 0.4444444444x + x2 = 0

Move the constant term to the right:

Add '0.05555555556' to each side of the equation.
-0.05555555556 + 0.4444444444x + 0.05555555556 + x2 = 0 + 0.05555555556

Reorder the terms:
-0.05555555556 + 0.05555555556 + 0.4444444444x + x2 = 0 + 0.05555555556

Combine like terms: -0.05555555556 + 0.05555555556 = 0.00000000000
0.00000000000 + 0.4444444444x + x2 = 0 + 0.05555555556
0.4444444444x + x2 = 0 + 0.05555555556

Combine like terms: 0 + 0.05555555556 = 0.05555555556
0.4444444444x + x2 = 0.05555555556

The x term is 0.4444444444x.  Take half its coefficient (0.2222222222).
Square it (0.04938271604) and add it to both sides.

Add '0.04938271604' to each side of the equation.
0.4444444444x + 0.04938271604 + x2 = 0.05555555556 + 0.04938271604

Reorder the terms:
0.04938271604 + 0.4444444444x + x2 = 0.05555555556 + 0.04938271604

Combine like terms: 0.05555555556 + 0.04938271604 = 0.1049382716
0.04938271604 + 0.4444444444x + x2 = 0.1049382716

Factor a perfect square on the left side:
(x + 0.2222222222)(x + 0.2222222222) = 0.1049382716

Calculate the square root of the right side: 0.323941772

Break this problem into two subproblems by setting 
(x + 0.2222222222) equal to 0.323941772 and -0.323941772.

Subproblem 1

x + 0.2222222222 = 0.323941772 Simplifying x + 0.2222222222 = 0.323941772 Reorder the terms: 0.2222222222 + x = 0.323941772 Solving 0.2222222222 + x = 0.323941772 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.2222222222' to each side of the equation. 0.2222222222 + -0.2222222222 + x = 0.323941772 + -0.2222222222 Combine like terms: 0.2222222222 + -0.2222222222 = 0.0000000000 0.0000000000 + x = 0.323941772 + -0.2222222222 x = 0.323941772 + -0.2222222222 Combine like terms: 0.323941772 + -0.2222222222 = 0.1017195498 x = 0.1017195498 Simplifying x = 0.1017195498

Subproblem 2

x + 0.2222222222 = -0.323941772 Simplifying x + 0.2222222222 = -0.323941772 Reorder the terms: 0.2222222222 + x = -0.323941772 Solving 0.2222222222 + x = -0.323941772 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.2222222222' to each side of the equation. 0.2222222222 + -0.2222222222 + x = -0.323941772 + -0.2222222222 Combine like terms: 0.2222222222 + -0.2222222222 = 0.0000000000 0.0000000000 + x = -0.323941772 + -0.2222222222 x = -0.323941772 + -0.2222222222 Combine like terms: -0.323941772 + -0.2222222222 = -0.5461639942 x = -0.5461639942 Simplifying x = -0.5461639942

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.1017195498, -0.5461639942}

See similar equations:

| 26.6=1+0.25 | | 21=-5(7x+8) | | 2(2x+3)=21-3(x-2) | | 6(4w+8)=28 | | 4(4w+3)=5 | | -5(2t+6)=30 | | -10(s+2)=-14 | | 3x/4-1/3=1-2/3(x-1/6) | | -1(c-9)=12 | | 0.60000001+-3= | | 3x+4x*8x=9 | | .40(x+300)=.10(300)+.50x | | -10(s+2)=55 | | -6-4(1-2b)=22 | | -1(n-6)=3 | | 8-4-(3x+4)=1x+2 | | 29=-7k+8k | | 141+-51= | | 2x^5-24x^4+100x^3+400x^2+3750x+5000=0 | | 142000/74000 | | 74000/142000 | | 3x+2y=179 | | -0.2=y/3 | | 2/3(2x-3)=1/1/2(3x-2) | | 2/3-6/7=x | | 8b+3b=(8+3)b | | 12x-y=6 | | 2y+4y=3y | | 1/2-1/4=x | | 2k-3+4x=39 | | 2a=34-3/2 | | 7x-3(2x+5)=3x-4 |

Equations solver categories