x^2-5x+21=0

Simple and best practice solution for x^2-5x+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^2-5x+21=0 equation:


Simplifying
x2 + -5x + 21 = 0

Reorder the terms:
21 + -5x + x2 = 0

Solving
21 + -5x + 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 + -5x + -21 + x2 = 0 + -21

Reorder the terms:
21 + -21 + -5x + x2 = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -5x + x2 = 0 + -21
-5x + x2 = 0 + -21

Combine like terms: 0 + -21 = -21
-5x + x2 = -21

The x term is -5x.  Take half its coefficient (-2.5).
Square it (6.25) and add it to both sides.

Add '6.25' to each side of the equation.
-5x + 6.25 + x2 = -21 + 6.25

Reorder the terms:
6.25 + -5x + x2 = -21 + 6.25

Combine like terms: -21 + 6.25 = -14.75
6.25 + -5x + x2 = -14.75

Factor a perfect square on the left side:
(x + -2.5)(x + -2.5) = -14.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| 270=45(180) | | 3x=x^2-6x-6x+36 | | 6x-x*2=0 | | (4x-3)(16x^2-24x+29)=0 | | lnx^2+lnx=1 | | 9z-5=3x+5 | | 2y+3=8.25 | | 3x-5=42 | | 5x-46=76+10x | | 2(c+5)=3(2c+2) | | 2x+9(3)=2x+11(4) | | -3+5y=60 | | x+y=196 | | 10x+10-3x=5x-25+x | | -4x-2y=-1 | | 2s+3=20-1 | | K+15=49 | | 2u-9=u-8 | | 2x^2-2(x-2)=20 | | (4u-7)-(-13u+8)= | | 3(d+3)=15 | | 3x+3=9x | | 2.5h-15=4j | | 3y-7=-2 | | 6x+35+x=15(x+4)-25 | | 2(a-6)=36 | | -4.2=1.7+x | | 0.4x-0.3y=1.4 | | 4.2=1.7+x | | -0.2x-0.3=0.2 | | x^2+4kx+5k=0 | | 3(x+5)+x=-7 |

Equations solver categories