-2x^2+6x-21=0

Simple and best practice solution for -2x^2+6x-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 -2x^2+6x-21=0 equation:


Simplifying
-2x2 + 6x + -21 = 0

Reorder the terms:
-21 + 6x + -2x2 = 0

Solving
-21 + 6x + -2x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
-2 the coefficient of the squared term: 

Divide each side by '-2'.
10.5 + -3x + x2 = 0

Move the constant term to the right:

Add '-10.5' to each side of the equation.
10.5 + -3x + -10.5 + x2 = 0 + -10.5

Reorder the terms:
10.5 + -10.5 + -3x + x2 = 0 + -10.5

Combine like terms: 10.5 + -10.5 = 0.0
0.0 + -3x + x2 = 0 + -10.5
-3x + x2 = 0 + -10.5

Combine like terms: 0 + -10.5 = -10.5
-3x + x2 = -10.5

The x term is -3x.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3x + 2.25 + x2 = -10.5 + 2.25

Reorder the terms:
2.25 + -3x + x2 = -10.5 + 2.25

Combine like terms: -10.5 + 2.25 = -8.25
2.25 + -3x + x2 = -8.25

Factor a perfect square on the left side:
(x + -1.5)(x + -1.5) = -8.25

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| 5(w-3)+2(w+3)-22=7(w+8)-12 | | X=15+0.4x | | 15t=-4.9t^2+32t+0.2 | | -0.6r(r+0.2)=1.8 | | 17x-4+4x-9=5x+8+2x+4-2x | | 0=5x-4-4y | | 6y-8(2y-8)= | | -16t^2+96t+432=576 | | 9e+4=14+8c | | 3(5)+y=16 | | -0.6r(r+0.2)=18 | | 4-(3c-1)6-(3c-1)= | | Y=-3x^2+24x-15 | | 6x+6(x-20)=660 | | x(16-2x)(12-2x)=60 | | 5-6[2t-2(the+3)]=8-t | | 3n-7=62 | | 122=w-58 | | -7v-21=7(v+1) | | x^5-2x^3=-297 | | 1-27x^6=0 | | 8(y-1)=6y+2 | | (4*3)+8+2*(12-10)= | | (3w+4)(6-w)=0 | | (4*3)+8+2x(12-10)= | | -6x+32=-2(x-4) | | 22=2(u-3)+2u | | -6w+3(w+5)=24 | | -12z=-28 | | 42+8+m=70 | | 3=-3v+6(v-2) | | Y+x=68 |

Equations solver categories