x^2-10x=21

Simple and best practice solution for x^2-10x=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^2-10x=21 equation:


Simplifying
x2 + -10x = 21

Reorder the terms:
-10x + x2 = 21

Solving
-10x + x2 = 21

Solving for variable 'x'.

Reorder the terms:
-21 + -10x + x2 = 21 + -21

Combine like terms: 21 + -21 = 0
-21 + -10x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '21' to each side of the equation.
-21 + -10x + 21 + x2 = 0 + 21

Reorder the terms:
-21 + 21 + -10x + x2 = 0 + 21

Combine like terms: -21 + 21 = 0
0 + -10x + x2 = 0 + 21
-10x + x2 = 0 + 21

Combine like terms: 0 + 21 = 21
-10x + x2 = 21

The x term is -10x.  Take half its coefficient (-5).
Square it (25) and add it to both sides.

Add '25' to each side of the equation.
-10x + 25 + x2 = 21 + 25

Reorder the terms:
25 + -10x + x2 = 21 + 25

Combine like terms: 21 + 25 = 46
25 + -10x + x2 = 46

Factor a perfect square on the left side:
(x + -5)(x + -5) = 46

Calculate the square root of the right side: 6.782329983

Break this problem into two subproblems by setting 
(x + -5) equal to 6.782329983 and -6.782329983.

Subproblem 1

x + -5 = 6.782329983 Simplifying x + -5 = 6.782329983 Reorder the terms: -5 + x = 6.782329983 Solving -5 + x = 6.782329983 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '5' to each side of the equation. -5 + 5 + x = 6.782329983 + 5 Combine like terms: -5 + 5 = 0 0 + x = 6.782329983 + 5 x = 6.782329983 + 5 Combine like terms: 6.782329983 + 5 = 11.782329983 x = 11.782329983 Simplifying x = 11.782329983

Subproblem 2

x + -5 = -6.782329983 Simplifying x + -5 = -6.782329983 Reorder the terms: -5 + x = -6.782329983 Solving -5 + x = -6.782329983 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '5' to each side of the equation. -5 + 5 + x = -6.782329983 + 5 Combine like terms: -5 + 5 = 0 0 + x = -6.782329983 + 5 x = -6.782329983 + 5 Combine like terms: -6.782329983 + 5 = -1.782329983 x = -1.782329983 Simplifying x = -1.782329983

Solution

The solution to the problem is based on the solutions from the subproblems. x = {11.782329983, -1.782329983}

See similar equations:

| 4x^3+(2*108)x=0 | | 6.2x+1.2=8.9 | | 70=s | | 4x-2=2x-2+2x | | 20=7*x+13 | | 3x+4=2x+x+4 | | 2(x+7)=2x+7 | | -12-7x=-103 | | 0.2n=6 | | 4b+6=32 | | a(8d-5)+13=12d-2 | | 198X=2376 | | G+26=324 | | 9=13+x | | 4n=56 | | n=(.25)(3.5) | | -3(w+4)=3w-8+2(5w+2) | | 7+5b=27 | | -4(-6w+4)-3w=5(w-4)-6 | | 8x+11=27 | | -4-(1)= | | 5(u+3)=-3(5u-9)+5u | | 63=3ab+3 | | t+8=-3 | | 2+4n=n+10 | | x+9/2=23/5-x-3/5 | | 65-40= | | 65(40)= | | 6x-16=43 | | 55-35= | | x-35=20 | | (8x+3)+6=2 |

Equations solver categories