21x^2-21x+40=0

Simple and best practice solution for 21x^2-21x+40=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 21x^2-21x+40=0 equation:


Simplifying
21x2 + -21x + 40 = 0

Reorder the terms:
40 + -21x + 21x2 = 0

Solving
40 + -21x + 21x2 = 0

Solving for variable 'x'.

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

Divide each side by '21'.
1.904761905 + -1x + x2 = 0

Move the constant term to the right:

Add '-1.904761905' to each side of the equation.
1.904761905 + -1x + -1.904761905 + x2 = 0 + -1.904761905

Reorder the terms:
1.904761905 + -1.904761905 + -1x + x2 = 0 + -1.904761905

Combine like terms: 1.904761905 + -1.904761905 = 0.000000000
0.000000000 + -1x + x2 = 0 + -1.904761905
-1x + x2 = 0 + -1.904761905

Combine like terms: 0 + -1.904761905 = -1.904761905
-1x + x2 = -1.904761905

The x term is -1x.  Take half its coefficient (-0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-1x + 0.25 + x2 = -1.904761905 + 0.25

Reorder the terms:
0.25 + -1x + x2 = -1.904761905 + 0.25

Combine like terms: -1.904761905 + 0.25 = -1.654761905
0.25 + -1x + x2 = -1.654761905

Factor a perfect square on the left side:
(x + -0.5)(x + -0.5) = -1.654761905

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| M-4.3=9.54 | | 7/12*3/28 | | x--5=3 | | 18=.4f | | -5+5x-3x=5 | | m=81+4 | | g/8=8 | | 3(5x-6)=30-3(2x-5) | | 1.8-6.2=-37.4-1.3x | | -6x-1+x=-46 | | 5r^2+50r+125=0 | | 91=r+63 | | 5r^2+50r+125=100 | | 10+x+6x=-46 | | 2x+(5x-30)=180 | | 10+x+6x=-466 | | g+21=100 | | F(x)=-3.6x^2+4.8x | | c/10=8 | | -8x+13=-2(4x-7) | | 2x-7+2x=9 | | x+3+5x=-45 | | .25x+3=.5x-1 | | -6+3x-7x=-26 | | 8(4u+-1)+-12u=11(2u+-6) | | -10x^2-34x=12 | | 1+5x+7x=-59 | | (P+1)=7+P | | 2t^3-3t^2=0 | | 10-4x+3x=6 | | 3x+12=-51-6x | | 4(5f+3)-34= |

Equations solver categories