9x^2+21x+42=0

Simple and best practice solution for 9x^2+21x+42=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 9x^2+21x+42=0 equation: 


Simplifying
9x2 + 21x + 42 = 0

Reorder the terms:
42 + 21x + 9x2 = 0

Solving
42 + 21x + 9x2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '3'.
3(14 + 7x + 3x2) = 0

Ignore the factor 3.

Subproblem 1
Set the factor '(14 + 7x + 3x2)' equal to zero and attempt to solve:

Simplifying
14 + 7x + 3x2 = 0

Solving
14 + 7x + 3x2 = 0

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

Divide each side by '3'.
4.666666667 + 2.333333333x + x2 = 0

Move the constant term to the right:

Add '-4.666666667' to each side of the equation.
4.666666667 + 2.333333333x + -4.666666667 + x2 = 0 + -4.666666667

Reorder the terms:
4.666666667 + -4.666666667 + 2.333333333x + x2 = 0 + -4.666666667

Combine like terms: 4.666666667 + -4.666666667 = 0.000000000
0.000000000 + 2.333333333x + x2 = 0 + -4.666666667
2.333333333x + x2 = 0 + -4.666666667

Combine like terms: 0 + -4.666666667 = -4.666666667
2.333333333x + x2 = -4.666666667

The x term is 2.333333333x.  Take half its coefficient (1.166666667).
Square it (1.361111112) and add it to both sides.

Add '1.361111112' to each side of the equation.
2.333333333x + 1.361111112 + x2 = -4.666666667 + 1.361111112

Reorder the terms:
1.361111112 + 2.333333333x + x2 = -4.666666667 + 1.361111112

Combine like terms: -4.666666667 + 1.361111112 = -3.305555555
1.361111112 + 2.333333333x + x2 = -3.305555555

Factor a perfect square on the left side:
(x + 1.166666667)(x + 1.166666667) = -3.305555555

Can't calculate square root of the right side.

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.

See similar equations:

| 2(3n-8)=-13+7n | | 2y=3.5x+3 | | 3t+22=46 | | 8y+10x=182 | | U(77x-61y)-(65x+39y)= | | 4+4r=24 | | 48x-13-15x=-64 | | 9x+2=6x | | -434=-31x | | -8x+6+9x=17+x | | 8y+10x=180 | | 28+3n=-n+6(7n-8) | | 1=31-z | | 40/72 | | 2/5y-5=-3 | | 6(3x-6)+8x= | | 48x-13-18x=166 | | -11=x+(-5) | | -0.5x+9.19=-0.7+3.59 | | j/4-5=0 | | 5-(4x+6)=-10-7x | | 20+3q=41 | | 4^2x=32^1/2 | | -9y-2=-8y-9 | | 16b^2=60+68b | | Log(15x)=1 | | 3*sqrt(2+x)-6*sqrt(2-x)+sqrt(4-x^2)=10-3*x | | 18-3b=3(1-4b)+6b | | x=5/3x-2 | | n+1+n+3=132 | | t+12=0 | | (69x+58y)-(17x+32y)= |

Equations solver categories