x^2-2x+21=0

Simple and best practice solution for x^2-2x+21=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 x^2-2x+21=0 equation:


Simplifying
x2 + -2x + 21 = 0

Reorder the terms:
21 + -2x + x2 = 0

Solving
21 + -2x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-21' to each side of the equation.
21 + -2x + -21 + x2 = 0 + -21

Reorder the terms:
21 + -21 + -2x + x2 = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -2x + x2 = 0 + -21
-2x + x2 = 0 + -21

Combine like terms: 0 + -21 = -21
-2x + x2 = -21

The x term is -2x.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2x + 1 + x2 = -21 + 1

Reorder the terms:
1 + -2x + x2 = -21 + 1

Combine like terms: -21 + 1 = -20
1 + -2x + x2 = -20

Factor a perfect square on the left side:
(x + -1)(x + -1) = -20

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| 5x+2x=-14 | | 11d=135 | | 27+z=47 | | 3x+7=43-7x | | g-35=62 | | 5(2x-2)=3(x-1)+7 | | h-3=6 | | 7x+14=84 | | 3(x-4)-(x+2)=10 | | 5x^4+7x^2-6= | | x^4-8x^2-33=0 | | -3x+7(3x-5)=-15-2x | | 4w^2+19w+21=0 | | 54=32+w | | 9x+7.28=5x+13 | | 3x+32=10x-52 | | H+5H+3=57 | | 17=19+x | | 19=z-21 | | 1=x-10 | | 10x-2x+3x= | | u-4=1 | | 5x^2-x+2=0 | | 7m+2m= | | 2(14x)-20= | | 28x-20= | | 77-6x=12x+19 | | x^2=4x-9 | | 2(5x+9)-20= | | 3(4x-5)-5(2x-3)=4(x-1) | | dx=cy-f | | -7(x+7)+5(2x+1)= |

Equations solver categories