x=-5x^2+8x+9

Simple and best practice solution for x=-5x^2+8x+9 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=-5x^2+8x+9 equation:


Simplifying
x = -5x2 + 8x + 9

Reorder the terms:
x = 9 + 8x + -5x2

Solving
x = 9 + 8x + -5x2

Solving for variable 'x'.

Reorder the terms:
-9 + x + -8x + 5x2 = 9 + 8x + -5x2 + -9 + -8x + 5x2

Combine like terms: x + -8x = -7x
-9 + -7x + 5x2 = 9 + 8x + -5x2 + -9 + -8x + 5x2

Reorder the terms:
-9 + -7x + 5x2 = 9 + -9 + 8x + -8x + -5x2 + 5x2

Combine like terms: 9 + -9 = 0
-9 + -7x + 5x2 = 0 + 8x + -8x + -5x2 + 5x2
-9 + -7x + 5x2 = 8x + -8x + -5x2 + 5x2

Combine like terms: 8x + -8x = 0
-9 + -7x + 5x2 = 0 + -5x2 + 5x2
-9 + -7x + 5x2 = -5x2 + 5x2

Combine like terms: -5x2 + 5x2 = 0
-9 + -7x + 5x2 = 0

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

Divide each side by '5'.
-1.8 + -1.4x + x2 = 0

Move the constant term to the right:

Add '1.8' to each side of the equation.
-1.8 + -1.4x + 1.8 + x2 = 0 + 1.8

Reorder the terms:
-1.8 + 1.8 + -1.4x + x2 = 0 + 1.8

Combine like terms: -1.8 + 1.8 = 0.0
0.0 + -1.4x + x2 = 0 + 1.8
-1.4x + x2 = 0 + 1.8

Combine like terms: 0 + 1.8 = 1.8
-1.4x + x2 = 1.8

The x term is -1.4x.  Take half its coefficient (-0.7).
Square it (0.49) and add it to both sides.

Add '0.49' to each side of the equation.
-1.4x + 0.49 + x2 = 1.8 + 0.49

Reorder the terms:
0.49 + -1.4x + x2 = 1.8 + 0.49

Combine like terms: 1.8 + 0.49 = 2.29
0.49 + -1.4x + x2 = 2.29

Factor a perfect square on the left side:
(x + -0.7)(x + -0.7) = 2.29

Calculate the square root of the right side: 1.513274595

Break this problem into two subproblems by setting 
(x + -0.7) equal to 1.513274595 and -1.513274595.

Subproblem 1

x + -0.7 = 1.513274595 Simplifying x + -0.7 = 1.513274595 Reorder the terms: -0.7 + x = 1.513274595 Solving -0.7 + x = 1.513274595 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.7' to each side of the equation. -0.7 + 0.7 + x = 1.513274595 + 0.7 Combine like terms: -0.7 + 0.7 = 0.0 0.0 + x = 1.513274595 + 0.7 x = 1.513274595 + 0.7 Combine like terms: 1.513274595 + 0.7 = 2.213274595 x = 2.213274595 Simplifying x = 2.213274595

Subproblem 2

x + -0.7 = -1.513274595 Simplifying x + -0.7 = -1.513274595 Reorder the terms: -0.7 + x = -1.513274595 Solving -0.7 + x = -1.513274595 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.7' to each side of the equation. -0.7 + 0.7 + x = -1.513274595 + 0.7 Combine like terms: -0.7 + 0.7 = 0.0 0.0 + x = -1.513274595 + 0.7 x = -1.513274595 + 0.7 Combine like terms: -1.513274595 + 0.7 = -0.813274595 x = -0.813274595 Simplifying x = -0.813274595

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.213274595, -0.813274595}

See similar equations:

| x^3+x^2+3*x+5=0 | | 2x-(5a+7x)=8x+(-3x+7a)-2a | | 3=j+2 | | f(x)=-5x^2+8x+9 | | 15(m+5)-3(8m+7)= | | 125x^2=12 | | -x^2-6x-8= | | -1=-5+I | | 6+2r-3=6r+3-3r | | 3[7x-2(y-1)]= | | 2=H-4 | | 2=H+4 | | u-1/8 | | -3x^2-6x-8= | | m^2-2*m+2=0 | | 4(x-2)-6(9x+7)= | | z^2-11z+19=-5 | | u-2/4 | | 9x+4x=78 | | x^2-2*m+2=0 | | -3=14+g | | y/4=-30 | | 2x^2-62x-140=0 | | I=-20x^2+400x | | -4=6(t-4)-5t | | 500t=200(t+4) | | 2=4+f | | (8x^4)^1/3 | | 2/3(6x+17) | | n=16-m | | -7+11=p+7 | | 15x+25x^2= |

Equations solver categories