2x(4x-10)=21

Simple and best practice solution for 2x(4x-10)=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 2x(4x-10)=21 equation:


Simplifying
2x(4x + -10) = 21

Reorder the terms:
2x(-10 + 4x) = 21
(-10 * 2x + 4x * 2x) = 21
(-20x + 8x2) = 21

Solving
-20x + 8x2 = 21

Solving for variable 'x'.

Reorder the terms:
-21 + -20x + 8x2 = 21 + -21

Combine like terms: 21 + -21 = 0
-21 + -20x + 8x2 = 0

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

Divide each side by '8'.
-2.625 + -2.5x + x2 = 0

Move the constant term to the right:

Add '2.625' to each side of the equation.
-2.625 + -2.5x + 2.625 + x2 = 0 + 2.625

Reorder the terms:
-2.625 + 2.625 + -2.5x + x2 = 0 + 2.625

Combine like terms: -2.625 + 2.625 = 0.000
0.000 + -2.5x + x2 = 0 + 2.625
-2.5x + x2 = 0 + 2.625

Combine like terms: 0 + 2.625 = 2.625
-2.5x + x2 = 2.625

The x term is -2.5x.  Take half its coefficient (-1.25).
Square it (1.5625) and add it to both sides.

Add '1.5625' to each side of the equation.
-2.5x + 1.5625 + x2 = 2.625 + 1.5625

Reorder the terms:
1.5625 + -2.5x + x2 = 2.625 + 1.5625

Combine like terms: 2.625 + 1.5625 = 4.1875
1.5625 + -2.5x + x2 = 4.1875

Factor a perfect square on the left side:
(x + -1.25)(x + -1.25) = 4.1875

Calculate the square root of the right side: 2.046338193

Break this problem into two subproblems by setting 
(x + -1.25) equal to 2.046338193 and -2.046338193.

Subproblem 1

x + -1.25 = 2.046338193 Simplifying x + -1.25 = 2.046338193 Reorder the terms: -1.25 + x = 2.046338193 Solving -1.25 + x = 2.046338193 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.25' to each side of the equation. -1.25 + 1.25 + x = 2.046338193 + 1.25 Combine like terms: -1.25 + 1.25 = 0.00 0.00 + x = 2.046338193 + 1.25 x = 2.046338193 + 1.25 Combine like terms: 2.046338193 + 1.25 = 3.296338193 x = 3.296338193 Simplifying x = 3.296338193

Subproblem 2

x + -1.25 = -2.046338193 Simplifying x + -1.25 = -2.046338193 Reorder the terms: -1.25 + x = -2.046338193 Solving -1.25 + x = -2.046338193 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.25' to each side of the equation. -1.25 + 1.25 + x = -2.046338193 + 1.25 Combine like terms: -1.25 + 1.25 = 0.00 0.00 + x = -2.046338193 + 1.25 x = -2.046338193 + 1.25 Combine like terms: -2.046338193 + 1.25 = -0.796338193 x = -0.796338193 Simplifying x = -0.796338193

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.296338193, -0.796338193}

See similar equations:

| 9n+4=76 | | 2m+(9m+81m)= | | p^2-3p+6=6 | | 2x(7x-2)=0 | | 6x-2(x-3)=4+3x | | t=25+36 | | 9+3(y-4)=27 | | 4x^2+12x+8=0 | | 7(a+2)=30.1 | | 6z+3z-6=0 | | 14-6n=-40 | | z-2.9=3.4 | | 4x=28-x | | 79.9=9c-2 | | 17-(2x-6)= | | -8n(10n-1)=0 | | 7e-7=28.7 | | 4x^2+12x-4=0 | | 7x-7=28 | | 9p=67.5 | | 2c-8c=0 | | 7(x-5)=-7 | | 8(a+5)=80 | | 15=16x-14x | | (4x+20)-3(2x+10)+3(x+5)=0 | | 4y+y=-20 | | 2c-4c=0 | | x^3+21x+7.88=0 | | 4x+7x=4 | | 55=9c-8 | | 4e-5=15 | | 8x^9=6x^6 |

Equations solver categories