x^2+4.2x+9=0

Simple and best practice solution for x^2+4.2x+9=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+4.2x+9=0 equation:


Simplifying
x2 + 4.2x + 9 = 0

Reorder the terms:
9 + 4.2x + x2 = 0

Solving
9 + 4.2x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-9' to each side of the equation.
9 + 4.2x + -9 + x2 = 0 + -9

Reorder the terms:
9 + -9 + 4.2x + x2 = 0 + -9

Combine like terms: 9 + -9 = 0
0 + 4.2x + x2 = 0 + -9
4.2x + x2 = 0 + -9

Combine like terms: 0 + -9 = -9
4.2x + x2 = -9

The x term is 4.2x.  Take half its coefficient (2.1).
Square it (4.41) and add it to both sides.

Add '4.41' to each side of the equation.
4.2x + 4.41 + x2 = -9 + 4.41

Reorder the terms:
4.41 + 4.2x + x2 = -9 + 4.41

Combine like terms: -9 + 4.41 = -4.59
4.41 + 4.2x + x2 = -4.59

Factor a perfect square on the left side:
(x + 2.1)(x + 2.1) = -4.59

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| log(7x-9)=log(x+2)+log(8) | | -5=-20+(-15)-1 | | (9x+8y)+7z= | | -2x-25=5(-2x-5) | | 2x^2+3x+2=16 | | 7t-15=8 | | 2x/3-14-19=0 | | 38-5x=2(x-2) | | 2*x/3-14=19 | | 5(6x-8)-7=-19+2x | | 6n-22=-(n+8) | | 3=18x+9x-1 | | 4z-20=7+18(z+4) | | 7c-6=3c+5 | | -32-7x=6(8-7x)-5x | | 9+1=11 | | 3x-.24=0.36+.52x | | -24-5p=-6(p+4)+7p | | 100v*5=1000 | | 100v*5=100 | | 460=x+3x | | 12c=30 | | 4a*3=12 | | 4a*3b=12 | | 12(z+12)=2 | | 10x-3(8-5x)=-40 | | 6(7-x)+x=4-x | | b+a= | | 12x=16x+11 | | x^2-6xy=-20 | | 32z^2+56z^2-162=0 | | 18+9e=10+11e |

Equations solver categories