SOLUTION: Solve the equation by completing the square and applying the square root property. Write imaginary solutions in the form a+bį. 2a^2+4a+5=0 2a^2+4a=-5 ((2a^2)/2)+(4a/2))=(-5

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Solve the equation by completing the square and applying the square root property. Write imaginary solutions in the form a+bį. 2a^2+4a+5=0 2a^2+4a=-5 ((2a^2)/2)+(4a/2))=(-5      Log On


   



Question 1059706: Solve the equation by completing the square and applying the square root property. Write imaginary solutions in the form a+bį.
2a^2+4a+5=0
2a^2+4a=-5
((2a^2)/2)+(4a/2))=(-5/2)
(1/2(2)^2)=1
a^2+2a+1=-5/2+1
(a+1)^2=(-5/2)+(2/2)
(a+1)^2=-3/2
sqrt (a+1)^2=sqrt(-3/2)
a+1=+or- sqrt(3/2)į

Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Try it this way:

2a%5E2%2B4a=-5
2%28a%5E2%2B2a%29=-5
and then INSIDE the parentheses, add the term %282%2F2%29%5E2=1, but on the right-hand member, you must account for the factor in the left-side member which has been factorized....

2%28a%5E2%2B2a%2B1%29=-5%2B2%2A1
2%28a%5E2%2B2a%2B1%29=-5%2B2

If that is clear for you, then continue.

Answer by MathTherapy(10551) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the equation by completing the square and applying the square root property. Write imaginary solutions in the form a+bį.
2a^2+4a+5=0
2a^2+4a=-5
((2a^2)/2)+(4a/2))=(-5/2)
(1/2)(2)^2) = 1
a^2+2a+1=-5/2+1
(a+1)^2=(-5/2)+(2/2)
(a+1)^2=-3/2
sqrt (a+1)^2=sqrt(-3/2)
a+1=+or- sqrt(3/2)į
2a%5E2+%2B+4a+%2B+5+=+0 
2a%5E2+%2B+4a+=+-+5 <======== Correct
2a%5E2%2F2+%2B+%284a%2F2%29+=+%28-+5%29%2F2 <======= Correct
%28%281%2F2%29+%2A+2%29%5E2+=+1 <======= Correct
a%5E2+%2B+2a+%2B+1+=+%28-+5%29%2F2+%2B+1 <======= Correct
I must say, so far, I'm impressed
%28a+%2B+1%29%5E2+=+%28-+5%29%2F2+%2B+2%2F2 <===== Correct
%28a+%2B+1%29%5E2+=+%28-+3%29%2F2 <====== Correct
sqrt%28%28a+%2B+1%29%5E2%29+=+%22+%22%2B-sqrt%28-+3%2F2%29
a+%2B+1+=+%22+%22%2B-sqrt%28-+3%2F2%29
a+%2B+1+=+%22+%22%2B-+sqrt%283%2F2%29i <====== Correct
a+%2B+1+=+%22+%22%2B-+%28sqrt%283%29+%2A+sqrt%282%29%2F2%29+%2A+i =====> a+%2B+1+=+%22+%22%2B-+%28sqrt%286%29%2F2%29i =====> highlight%28highlight_green%28highlight%28a+=+-+1+%2B-+%28sqrt%286%29%2F2%29i%29%29%29