7x(3+x)-(x-3)=0

Simple and best practice solution for 7x(3+x)-(x-3)=0 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(3+x)-(x-3)=0 equation:


Simplifying
7x(3 + x) + -1(x + -3) = 0
(3 * 7x + x * 7x) + -1(x + -3) = 0
(21x + 7x2) + -1(x + -3) = 0

Reorder the terms:
21x + 7x2 + -1(-3 + x) = 0
21x + 7x2 + (-3 * -1 + x * -1) = 0
21x + 7x2 + (3 + -1x) = 0

Reorder the terms:
3 + 21x + -1x + 7x2 = 0

Combine like terms: 21x + -1x = 20x
3 + 20x + 7x2 = 0

Solving
3 + 20x + 7x2 = 0

Solving for variable 'x'.

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

Divide each side by '7'.
0.4285714286 + 2.857142857x + x2 = 0

Move the constant term to the right:

Add '-0.4285714286' to each side of the equation.
0.4285714286 + 2.857142857x + -0.4285714286 + x2 = 0 + -0.4285714286

Reorder the terms:
0.4285714286 + -0.4285714286 + 2.857142857x + x2 = 0 + -0.4285714286

Combine like terms: 0.4285714286 + -0.4285714286 = 0.0000000000
0.0000000000 + 2.857142857x + x2 = 0 + -0.4285714286
2.857142857x + x2 = 0 + -0.4285714286

Combine like terms: 0 + -0.4285714286 = -0.4285714286
2.857142857x + x2 = -0.4285714286

The x term is 2.857142857x.  Take half its coefficient (1.428571429).
Square it (2.040816328) and add it to both sides.

Add '2.040816328' to each side of the equation.
2.857142857x + 2.040816328 + x2 = -0.4285714286 + 2.040816328

Reorder the terms:
2.040816328 + 2.857142857x + x2 = -0.4285714286 + 2.040816328

Combine like terms: -0.4285714286 + 2.040816328 = 1.6122448994
2.040816328 + 2.857142857x + x2 = 1.6122448994

Factor a perfect square on the left side:
(x + 1.428571429)(x + 1.428571429) = 1.6122448994

Calculate the square root of the right side: 1.26974206

Break this problem into two subproblems by setting 
(x + 1.428571429) equal to 1.26974206 and -1.26974206.

Subproblem 1

x + 1.428571429 = 1.26974206 Simplifying x + 1.428571429 = 1.26974206 Reorder the terms: 1.428571429 + x = 1.26974206 Solving 1.428571429 + x = 1.26974206 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.428571429' to each side of the equation. 1.428571429 + -1.428571429 + x = 1.26974206 + -1.428571429 Combine like terms: 1.428571429 + -1.428571429 = 0.000000000 0.000000000 + x = 1.26974206 + -1.428571429 x = 1.26974206 + -1.428571429 Combine like terms: 1.26974206 + -1.428571429 = -0.158829369 x = -0.158829369 Simplifying x = -0.158829369

Subproblem 2

x + 1.428571429 = -1.26974206 Simplifying x + 1.428571429 = -1.26974206 Reorder the terms: 1.428571429 + x = -1.26974206 Solving 1.428571429 + x = -1.26974206 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.428571429' to each side of the equation. 1.428571429 + -1.428571429 + x = -1.26974206 + -1.428571429 Combine like terms: 1.428571429 + -1.428571429 = 0.000000000 0.000000000 + x = -1.26974206 + -1.428571429 x = -1.26974206 + -1.428571429 Combine like terms: -1.26974206 + -1.428571429 = -2.698313489 x = -2.698313489 Simplifying x = -2.698313489

Solution

The solution to the problem is based on the solutions from the subproblems. x = {-0.158829369, -2.698313489}

See similar equations:

| 5(x-30)=-(2x+138) | | 3(2(x-3)+3(2-x))=x+8 | | 43+3x=3+5x | | 625x-5=125 | | 3v-18=3v-18 | | 7x(3-x)-(x-3)=0 | | 0.5*x-5=10+x | | 5-5x=100 | | 7n-21+4n+20=35 | | 117.6=x-20 | | -15+3x=90 | | 7(n-3)+4(n+5)=1.25 | | 8x-x=4 | | 3x-83=187-3x | | -x+9=9-4x | | 2x+3(x-7)=44 | | 9-2x=x+2 | | 2x-(4+7x)= | | 12x^2-37x-10=0 | | ln(x^2-9)-ln(x+3)=0 | | 4+6x=11x+9 | | x^3-12x^2+12x-72=0 | | -10x+7=-5x-3 | | 5x+10=61 | | 4x+20=-3x-1 | | -3(5y-3)-y=-2(y-5) | | (-2d)(-3-7d)= | | 10x^2-6x-288=0 | | 2xy+y=-7 | | 4p-3=13(p-8) | | 2(3-2x)=7-(5x-3) | | 4(x+5)+11x=110 |

Equations solver categories