x-(4x-7)=5x(x+21)

Simple and best practice solution for x-(4x-7)=5x(x+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 x-(4x-7)=5x(x+21) equation:


Simplifying
x + -1(4x + -7) = 5x(x + 21)

Reorder the terms:
x + -1(-7 + 4x) = 5x(x + 21)
x + (-7 * -1 + 4x * -1) = 5x(x + 21)
x + (7 + -4x) = 5x(x + 21)

Reorder the terms:
7 + x + -4x = 5x(x + 21)

Combine like terms: x + -4x = -3x
7 + -3x = 5x(x + 21)

Reorder the terms:
7 + -3x = 5x(21 + x)
7 + -3x = (21 * 5x + x * 5x)
7 + -3x = (105x + 5x2)

Solving
7 + -3x = 105x + 5x2

Solving for variable 'x'.

Combine like terms: -3x + -105x = -108x
7 + -108x + -5x2 = 105x + 5x2 + -105x + -5x2

Reorder the terms:
7 + -108x + -5x2 = 105x + -105x + 5x2 + -5x2

Combine like terms: 105x + -105x = 0
7 + -108x + -5x2 = 0 + 5x2 + -5x2
7 + -108x + -5x2 = 5x2 + -5x2

Combine like terms: 5x2 + -5x2 = 0
7 + -108x + -5x2 = 0

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

Divide each side by '-5'.
-1.4 + 21.6x + x2 = 0

Move the constant term to the right:

Add '1.4' to each side of the equation.
-1.4 + 21.6x + 1.4 + x2 = 0 + 1.4

Reorder the terms:
-1.4 + 1.4 + 21.6x + x2 = 0 + 1.4

Combine like terms: -1.4 + 1.4 = 0.0
0.0 + 21.6x + x2 = 0 + 1.4
21.6x + x2 = 0 + 1.4

Combine like terms: 0 + 1.4 = 1.4
21.6x + x2 = 1.4

The x term is 21.6x.  Take half its coefficient (10.8).
Square it (116.64) and add it to both sides.

Add '116.64' to each side of the equation.
21.6x + 116.64 + x2 = 1.4 + 116.64

Reorder the terms:
116.64 + 21.6x + x2 = 1.4 + 116.64

Combine like terms: 1.4 + 116.64 = 118.04
116.64 + 21.6x + x2 = 118.04

Factor a perfect square on the left side:
(x + 10.8)(x + 10.8) = 118.04

Calculate the square root of the right side: 10.864621484

Break this problem into two subproblems by setting 
(x + 10.8) equal to 10.864621484 and -10.864621484.

Subproblem 1

x + 10.8 = 10.864621484 Simplifying x + 10.8 = 10.864621484 Reorder the terms: 10.8 + x = 10.864621484 Solving 10.8 + x = 10.864621484 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-10.8' to each side of the equation. 10.8 + -10.8 + x = 10.864621484 + -10.8 Combine like terms: 10.8 + -10.8 = 0.0 0.0 + x = 10.864621484 + -10.8 x = 10.864621484 + -10.8 Combine like terms: 10.864621484 + -10.8 = 0.064621484 x = 0.064621484 Simplifying x = 0.064621484

Subproblem 2

x + 10.8 = -10.864621484 Simplifying x + 10.8 = -10.864621484 Reorder the terms: 10.8 + x = -10.864621484 Solving 10.8 + x = -10.864621484 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-10.8' to each side of the equation. 10.8 + -10.8 + x = -10.864621484 + -10.8 Combine like terms: 10.8 + -10.8 = 0.0 0.0 + x = -10.864621484 + -10.8 x = -10.864621484 + -10.8 Combine like terms: -10.864621484 + -10.8 = -21.664621484 x = -21.664621484 Simplifying x = -21.664621484

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.064621484, -21.664621484}

See similar equations:

| 1.9+0.2x=0.3 | | 3(x+2.42)=2x | | 1/6(x-6)= | | 2.7x-43=1.8x+2 | | (x)=x(71-5x) | | 4+3x=40 | | 7x+3+7x=171 | | 2xy-x^3-5=0 | | 2m^5-3m^3-2m=0 | | 5x-4-x=-20 | | y/8-1/2=6 | | 3+7x=5-9x | | (x)=120+14x | | -8+4x=-48 | | 1/2x^2+3x-4=-4 | | 6c-8=8-6c | | 7-2(a-3)=-9 | | 7x^5+46x^3+24x=0 | | -6(2+6x)=60 | | =-4x^2+5x | | 4x-9=35x-9 | | 8r^2=128 | | 2c+5=-1 | | 3/2(7/3n+1)=3/2 | | 9x-y=27 | | 12+10+6+9+6+7+6= | | 7(6x+2)=476 | | 4x+2=5x-12 | | 384+864x+486x^2=0 | | -48=6+6x | | 98v^2-112v+32=0 | | -3e+8=-1 |

Equations solver categories