-x^2+3x+8=0

Simple and best practice solution for -x^2+3x+8=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 -x^2+3x+8=0 equation:


Simplifying
-1x2 + 3x + 8 = 0

Reorder the terms:
8 + 3x + -1x2 = 0

Solving
8 + 3x + -1x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-8 + -3x + x2 = 0

Move the constant term to the right:

Add '8' to each side of the equation.
-8 + -3x + 8 + x2 = 0 + 8

Reorder the terms:
-8 + 8 + -3x + x2 = 0 + 8

Combine like terms: -8 + 8 = 0
0 + -3x + x2 = 0 + 8
-3x + x2 = 0 + 8

Combine like terms: 0 + 8 = 8
-3x + x2 = 8

The x term is -3x.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3x + 2.25 + x2 = 8 + 2.25

Reorder the terms:
2.25 + -3x + x2 = 8 + 2.25

Combine like terms: 8 + 2.25 = 10.25
2.25 + -3x + x2 = 10.25

Factor a perfect square on the left side:
(x + -1.5)(x + -1.5) = 10.25

Calculate the square root of the right side: 3.201562119

Break this problem into two subproblems by setting 
(x + -1.5) equal to 3.201562119 and -3.201562119.

Subproblem 1

x + -1.5 = 3.201562119 Simplifying x + -1.5 = 3.201562119 Reorder the terms: -1.5 + x = 3.201562119 Solving -1.5 + x = 3.201562119 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.5' to each side of the equation. -1.5 + 1.5 + x = 3.201562119 + 1.5 Combine like terms: -1.5 + 1.5 = 0.0 0.0 + x = 3.201562119 + 1.5 x = 3.201562119 + 1.5 Combine like terms: 3.201562119 + 1.5 = 4.701562119 x = 4.701562119 Simplifying x = 4.701562119

Subproblem 2

x + -1.5 = -3.201562119 Simplifying x + -1.5 = -3.201562119 Reorder the terms: -1.5 + x = -3.201562119 Solving -1.5 + x = -3.201562119 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.5' to each side of the equation. -1.5 + 1.5 + x = -3.201562119 + 1.5 Combine like terms: -1.5 + 1.5 = 0.0 0.0 + x = -3.201562119 + 1.5 x = -3.201562119 + 1.5 Combine like terms: -3.201562119 + 1.5 = -1.701562119 x = -1.701562119 Simplifying x = -1.701562119

Solution

The solution to the problem is based on the solutions from the subproblems. x = {4.701562119, -1.701562119}

See similar equations:

| 3+7+6=2x+5+5x | | (-b^3)(d^2)=0 | | -4(v+1)=-6v-22 | | SolveV=lwhforH | | 3u-9=17(u-3) | | (4+x)+2= | | 650=0.3536x+14.857 | | 8(v+2)=-8v+32 | | 12log(e)(x)=33 | | 5x+2+-4x=7+-19 | | 11=3(y+5)-5y | | 12ln(x)=33 | | 5(x-5)-7x=-37 | | 7+78x=39x+20 | | Ln(4x-1)=1.6 | | -9x+7=2x+10+x+9 | | -4=3u+2(u+8) | | -n(-2n^2+3)= | | sqrt(x^2+10)-sqrt(x^2-2)= | | h(t)=-430t^2+75t+12 | | (-b^2)(d^2)=0 | | 0=20-16t^2+32t | | 18=6*x | | 3(2x)=28 | | q=-2p+26 | | c=mx+x | | D=-2p+26 | | 21x+9=10 | | 9x=9+6x+6 | | 2(4h-5h)=2h+10+h+15 | | 4x+20=6x-10 | | Log(6x+24)=2 |

Equations solver categories