(7x-21)(5x+13)=360

Simple and best practice solution for (7x-21)(5x+13)=360 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 (7x-21)(5x+13)=360 equation:


Simplifying
(7x + -21)(5x + 13) = 360

Reorder the terms:
(-21 + 7x)(5x + 13) = 360

Reorder the terms:
(-21 + 7x)(13 + 5x) = 360

Multiply (-21 + 7x) * (13 + 5x)
(-21(13 + 5x) + 7x * (13 + 5x)) = 360
((13 * -21 + 5x * -21) + 7x * (13 + 5x)) = 360
((-273 + -105x) + 7x * (13 + 5x)) = 360
(-273 + -105x + (13 * 7x + 5x * 7x)) = 360
(-273 + -105x + (91x + 35x2)) = 360

Combine like terms: -105x + 91x = -14x
(-273 + -14x + 35x2) = 360

Solving
-273 + -14x + 35x2 = 360

Solving for variable 'x'.

Reorder the terms:
-273 + -360 + -14x + 35x2 = 360 + -360

Combine like terms: -273 + -360 = -633
-633 + -14x + 35x2 = 360 + -360

Combine like terms: 360 + -360 = 0
-633 + -14x + 35x2 = 0

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

Divide each side by '35'.
-18.08571429 + -0.4x + x2 = 0

Move the constant term to the right:

Add '18.08571429' to each side of the equation.
-18.08571429 + -0.4x + 18.08571429 + x2 = 0 + 18.08571429

Reorder the terms:
-18.08571429 + 18.08571429 + -0.4x + x2 = 0 + 18.08571429

Combine like terms: -18.08571429 + 18.08571429 = 0.00000000
0.00000000 + -0.4x + x2 = 0 + 18.08571429
-0.4x + x2 = 0 + 18.08571429

Combine like terms: 0 + 18.08571429 = 18.08571429
-0.4x + x2 = 18.08571429

The x term is -0.4x.  Take half its coefficient (-0.2).
Square it (0.04) and add it to both sides.

Add '0.04' to each side of the equation.
-0.4x + 0.04 + x2 = 18.08571429 + 0.04

Reorder the terms:
0.04 + -0.4x + x2 = 18.08571429 + 0.04

Combine like terms: 18.08571429 + 0.04 = 18.12571429
0.04 + -0.4x + x2 = 18.12571429

Factor a perfect square on the left side:
(x + -0.2)(x + -0.2) = 18.12571429

Calculate the square root of the right side: 4.25743048

Break this problem into two subproblems by setting 
(x + -0.2) equal to 4.25743048 and -4.25743048.

Subproblem 1

x + -0.2 = 4.25743048 Simplifying x + -0.2 = 4.25743048 Reorder the terms: -0.2 + x = 4.25743048 Solving -0.2 + x = 4.25743048 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.2' to each side of the equation. -0.2 + 0.2 + x = 4.25743048 + 0.2 Combine like terms: -0.2 + 0.2 = 0.0 0.0 + x = 4.25743048 + 0.2 x = 4.25743048 + 0.2 Combine like terms: 4.25743048 + 0.2 = 4.45743048 x = 4.45743048 Simplifying x = 4.45743048

Subproblem 2

x + -0.2 = -4.25743048 Simplifying x + -0.2 = -4.25743048 Reorder the terms: -0.2 + x = -4.25743048 Solving -0.2 + x = -4.25743048 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.2' to each side of the equation. -0.2 + 0.2 + x = -4.25743048 + 0.2 Combine like terms: -0.2 + 0.2 = 0.0 0.0 + x = -4.25743048 + 0.2 x = -4.25743048 + 0.2 Combine like terms: -4.25743048 + 0.2 = -4.05743048 x = -4.05743048 Simplifying x = -4.05743048

Solution

The solution to the problem is based on the solutions from the subproblems. x = {4.45743048, -4.05743048}

See similar equations:

| 3x*3x*3x=0 | | -19x+8x^2=-x+2x^2 | | -8-5x^2=-28 | | 8-49-8/8-6 | | 9p^2+1=37 | | 4n^2-9=55 | | 3cos(2x)-5cosx-3=0 | | 5a-3=4 | | 5p^2-6=119 | | 7x+x^2=3x | | 4x-1/7=2 | | 8k^2+10=18 | | GCF=121X+14Y | | 7a^2-4=171 | | p^2-4=12 | | -18-9x+x^2=18 | | -9n^2=-324 | | -33+5x+x^2=9+4x | | -28+13x+3x^2=2+2x^2 | | -7u=14 | | 5p/3q/4p2/q | | v^2+5=9 | | 12.6-c=2x | | 8=(7x+5) | | n^2+7=56 | | 1.2*0.8*x=1.36 | | 8/9=y | | 3(y+2)+4=19 | | N=23 | | 18+11x=-7+7(10+8x) | | 6x+3y+z=20 | | 6(1x-2)=54 |

Equations solver categories