8x^2-16x=21

Simple and best practice solution for 8x^2-16x=21 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^2-16x=21 equation:


Simplifying
8x2 + -16x = 21

Reorder the terms:
-16x + 8x2 = 21

Solving
-16x + 8x2 = 21

Solving for variable 'x'.

Reorder the terms:
-21 + -16x + 8x2 = 21 + -21

Combine like terms: 21 + -21 = 0
-21 + -16x + 8x2 = 0

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

Divide each side by '8'.
-2.625 + -2x + x2 = 0

Move the constant term to the right:

Add '2.625' to each side of the equation.
-2.625 + -2x + 2.625 + x2 = 0 + 2.625

Reorder the terms:
-2.625 + 2.625 + -2x + x2 = 0 + 2.625

Combine like terms: -2.625 + 2.625 = 0.000
0.000 + -2x + x2 = 0 + 2.625
-2x + x2 = 0 + 2.625

Combine like terms: 0 + 2.625 = 2.625
-2x + x2 = 2.625

The x term is -2x.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2x + 1 + x2 = 2.625 + 1

Reorder the terms:
1 + -2x + x2 = 2.625 + 1

Combine like terms: 2.625 + 1 = 3.625
1 + -2x + x2 = 3.625

Factor a perfect square on the left side:
(x + -1)(x + -1) = 3.625

Calculate the square root of the right side: 1.903943276

Break this problem into two subproblems by setting 
(x + -1) equal to 1.903943276 and -1.903943276.

Subproblem 1

x + -1 = 1.903943276 Simplifying x + -1 = 1.903943276 Reorder the terms: -1 + x = 1.903943276 Solving -1 + x = 1.903943276 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + x = 1.903943276 + 1 Combine like terms: -1 + 1 = 0 0 + x = 1.903943276 + 1 x = 1.903943276 + 1 Combine like terms: 1.903943276 + 1 = 2.903943276 x = 2.903943276 Simplifying x = 2.903943276

Subproblem 2

x + -1 = -1.903943276 Simplifying x + -1 = -1.903943276 Reorder the terms: -1 + x = -1.903943276 Solving -1 + x = -1.903943276 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + x = -1.903943276 + 1 Combine like terms: -1 + 1 = 0 0 + x = -1.903943276 + 1 x = -1.903943276 + 1 Combine like terms: -1.903943276 + 1 = -0.903943276 x = -0.903943276 Simplifying x = -0.903943276

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.903943276, -0.903943276}

See similar equations:

| -2(1)+y=-6 | | 5x-2=8x-14 | | f(x)=6x^2+5x-10 | | 5x+3-2x=-2x+5x+3 | | U+4=-12 | | x*x+12x+27=0 | | Ax+2=5 | | 2(x-6)+8=3(x+1)-4 | | 6x+7(x+9)= | | -6v=-3(-15v-17) | | -3(9+11w)=-(12+18w) | | 3.54x+1=12.5216+x | | x^20-2x^10+1=0 | | x^30-2x^10+1=0 | | -2(-19+16)=3(16z+20)+18 | | X^30+x^10+1=0 | | 4d=12-6(-2d+10) | | 2x-3/4=0 | | 5(-7g+15)=-5-15g | | 15+19y+19=-19y-3(-15y+19) | | f(x)=2x-3/4=0 | | t^4-t^2-1=0 | | 5j=5(6j-10) | | 3(2)+y=12 | | 3x/5-6=9 | | 3(6)+y=12 | | x+11=2x-1 | | -7+6(-4q+19)=20-3-19q | | 3(4)+y=12 | | 8(x-4)+9-3(x+5)+38=0 | | 29x+5=30x+1 | | 8x-7+3-x=14-4x |

Equations solver categories