r^2+4r+20=0

Simple and best practice solution for r^2+4r+20=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 r^2+4r+20=0 equation:


Simplifying
r2 + 4r + 20 = 0

Reorder the terms:
20 + 4r + r2 = 0

Solving
20 + 4r + r2 = 0

Solving for variable 'r'.

Begin completing the square.

Move the constant term to the right:

Add '-20' to each side of the equation.
20 + 4r + -20 + r2 = 0 + -20

Reorder the terms:
20 + -20 + 4r + r2 = 0 + -20

Combine like terms: 20 + -20 = 0
0 + 4r + r2 = 0 + -20
4r + r2 = 0 + -20

Combine like terms: 0 + -20 = -20
4r + r2 = -20

The r term is 4r.  Take half its coefficient (2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
4r + 4 + r2 = -20 + 4

Reorder the terms:
4 + 4r + r2 = -20 + 4

Combine like terms: -20 + 4 = -16
4 + 4r + r2 = -16

Factor a perfect square on the left side:
(r + 2)(r + 2) = -16

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| v*9x= | | 2*3.14*r=7.12 | | 4y+8+5y=y^2+3 | | 7.12=2*3.14*r | | x^2+3x-138=0 | | 0=0y | | 30x+9=25x^2 | | 10(t-4)+5t=5(3t+5)-9 | | 3n=0 | | -4(5)([-2-3])= | | 6x+1=6x | | -(8y+3)-(-7y-5)=-5 | | 4-2x=6x-6 | | 0=1.7+12x-5x^2 | | 2x^2-7x-120=0 | | x-7.1=-3.7 | | s+25=13 | | -8(t-9)-(t+6)=4 | | 5x+6=4x+3 | | 3t+14=6t-13 | | 20-5q=0 | | 2x+2y=86 | | 3x+1y=86 | | 3x+2y=86 | | 14z^2-3=21z-3 | | 3*8= | | v*4x= | | -my-myb= | | 5x^4-30x^3+50x^2=0 | | (w*3w)=[(w+2)*(2w)] | | 3p^2-30p-11=6p | | 20x^3-15x^2= |

Equations solver categories