2x^2-8x=9

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


Simplifying
2x2 + -8x = 9

Reorder the terms:
-8x + 2x2 = 9

Solving
-8x + 2x2 = 9

Solving for variable 'x'.

Reorder the terms:
-9 + -8x + 2x2 = 9 + -9

Combine like terms: 9 + -9 = 0
-9 + -8x + 2x2 = 0

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

Divide each side by '2'.
-4.5 + -4x + x2 = 0

Move the constant term to the right:

Add '4.5' to each side of the equation.
-4.5 + -4x + 4.5 + x2 = 0 + 4.5

Reorder the terms:
-4.5 + 4.5 + -4x + x2 = 0 + 4.5

Combine like terms: -4.5 + 4.5 = 0.0
0.0 + -4x + x2 = 0 + 4.5
-4x + x2 = 0 + 4.5

Combine like terms: 0 + 4.5 = 4.5
-4x + x2 = 4.5

The x term is -4x.  Take half its coefficient (-2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
-4x + 4 + x2 = 4.5 + 4

Reorder the terms:
4 + -4x + x2 = 4.5 + 4

Combine like terms: 4.5 + 4 = 8.5
4 + -4x + x2 = 8.5

Factor a perfect square on the left side:
(x + -2)(x + -2) = 8.5

Calculate the square root of the right side: 2.915475947

Break this problem into two subproblems by setting 
(x + -2) equal to 2.915475947 and -2.915475947.

Subproblem 1

x + -2 = 2.915475947 Simplifying x + -2 = 2.915475947 Reorder the terms: -2 + x = 2.915475947 Solving -2 + x = 2.915475947 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2' to each side of the equation. -2 + 2 + x = 2.915475947 + 2 Combine like terms: -2 + 2 = 0 0 + x = 2.915475947 + 2 x = 2.915475947 + 2 Combine like terms: 2.915475947 + 2 = 4.915475947 x = 4.915475947 Simplifying x = 4.915475947

Subproblem 2

x + -2 = -2.915475947 Simplifying x + -2 = -2.915475947 Reorder the terms: -2 + x = -2.915475947 Solving -2 + x = -2.915475947 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2' to each side of the equation. -2 + 2 + x = -2.915475947 + 2 Combine like terms: -2 + 2 = 0 0 + x = -2.915475947 + 2 x = -2.915475947 + 2 Combine like terms: -2.915475947 + 2 = -0.915475947 x = -0.915475947 Simplifying x = -0.915475947

Solution

The solution to the problem is based on the solutions from the subproblems. x = {4.915475947, -0.915475947}

See similar equations:

| 10x^2=24x-8 | | (-8)*(-5)*(-2)*(y)=160 | | 6(n-1)=24 | | a(bx+9)=cx+3 | | (y)*(2)*(-3)=30 | | .35x+.8(70-x)=.5(70) | | (y)x(2)x(-3)=30 | | 4x^4-5x^3-4x^2=0 | | y=-2+6x+3x^2 | | -4/3(y-12)-1/6y= | | 4(3z+1)=14z | | 8p+4p-14=4p+7 | | 20d+13-12-43=0 | | 15=5x+220 | | (x-10)(x-3)=(x+3)(x+7) | | 64x^3+49x=0 | | -5.9(3p+5)-2.6(2p-4)= | | 8x+4x-21=63-9x | | (3x-15)(15x-3)=0 | | x^2+x+9=44 | | (5x-5)^1/3=-5 | | 5x+4x-28=42-5x | | X+3.2forx=5 | | (5x-5)1/3=-5 | | 24(2/3) | | 100[0.09(q+9)]= | | 20w+14w= | | 3x^2-24x-64=0 | | f(x+7)=7x-4 | | 1+5c=3.5 | | -0.4(6x+5)=3.6x | | 2n+3n=40 |

Equations solver categories