-5x=x^2+3x-21

Simple and best practice solution for -5x=x^2+3x-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 -5x=x^2+3x-21 equation:


Simplifying
-5x = x2 + 3x + -21

Reorder the terms:
-5x = -21 + 3x + x2

Solving
-5x = -21 + 3x + x2

Solving for variable 'x'.

Reorder the terms:
21 + -5x + -3x + -1x2 = -21 + 3x + x2 + 21 + -3x + -1x2

Combine like terms: -5x + -3x = -8x
21 + -8x + -1x2 = -21 + 3x + x2 + 21 + -3x + -1x2

Reorder the terms:
21 + -8x + -1x2 = -21 + 21 + 3x + -3x + x2 + -1x2

Combine like terms: -21 + 21 = 0
21 + -8x + -1x2 = 0 + 3x + -3x + x2 + -1x2
21 + -8x + -1x2 = 3x + -3x + x2 + -1x2

Combine like terms: 3x + -3x = 0
21 + -8x + -1x2 = 0 + x2 + -1x2
21 + -8x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
21 + -8x + -1x2 = 0

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-21 + 8x + x2 = 0

Move the constant term to the right:

Add '21' to each side of the equation.
-21 + 8x + 21 + x2 = 0 + 21

Reorder the terms:
-21 + 21 + 8x + x2 = 0 + 21

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

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

The x term is 8x.  Take half its coefficient (4).
Square it (16) and add it to both sides.

Add '16' to each side of the equation.
8x + 16 + x2 = 21 + 16

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

Combine like terms: 21 + 16 = 37
16 + 8x + x2 = 37

Factor a perfect square on the left side:
(x + 4)(x + 4) = 37

Calculate the square root of the right side: 6.08276253

Break this problem into two subproblems by setting 
(x + 4) equal to 6.08276253 and -6.08276253.

Subproblem 1

x + 4 = 6.08276253 Simplifying x + 4 = 6.08276253 Reorder the terms: 4 + x = 6.08276253 Solving 4 + x = 6.08276253 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-4' to each side of the equation. 4 + -4 + x = 6.08276253 + -4 Combine like terms: 4 + -4 = 0 0 + x = 6.08276253 + -4 x = 6.08276253 + -4 Combine like terms: 6.08276253 + -4 = 2.08276253 x = 2.08276253 Simplifying x = 2.08276253

Subproblem 2

x + 4 = -6.08276253 Simplifying x + 4 = -6.08276253 Reorder the terms: 4 + x = -6.08276253 Solving 4 + x = -6.08276253 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-4' to each side of the equation. 4 + -4 + x = -6.08276253 + -4 Combine like terms: 4 + -4 = 0 0 + x = -6.08276253 + -4 x = -6.08276253 + -4 Combine like terms: -6.08276253 + -4 = -10.08276253 x = -10.08276253 Simplifying x = -10.08276253

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.08276253, -10.08276253}

See similar equations:

| [4/(p-q)]-[2/(q-p)]= | | 2.85=3.80-x | | 4/13n=5.538 | | tan^22x=3 | | 0.09x+0.11(x+6000)=1460 | | 2(3+1)=8 | | 2x-(3-x)^1/2 | | 7(9x-8)=8244 | | -7s+7=-8s-14 | | N-14.888=3.111 | | 4f-11=13 | | x+11(4)=49 | | 6z-5+10+5z=180 | | 5(-2+4)=10 | | 143.50=205-x | | 8×3/28= | | 4(2x-1)=x+17 | | 180=225-x | | N/3.6=5 | | -10x+2(x-3)+6x=7x-15 | | 3x^2-5x+3=2x^2+3-12 | | 24.25+n=6.25 | | -7-17= | | 2x+2(x-1)=5x+7 | | log(3)(x^2+8x)=2 | | 2x+3(x-2)=6x+5 | | 5w=4w-19 | | 5x+8y=1435 | | -2x+6x-17=4(x-4)-38 | | X+8.21=16.21 | | 9w=2w+35 | | X+16.21=8.21 |

Equations solver categories