Question

how to solve 3a^2+6a+78=0 using solving quadratic equations by completing the square?

Answer 1

i would divide by 3 first

Answer 2

\[a^2+2a+26=0\]

Answer 3

clear answers will be complex right?

Answer 4

(a+1)^2+25=0

Answer 5

if that is not a problem we can go right to the answer by completing the square
\[(a^2+2a=-26\]
\[(a+1)^2=-26+1=-25\]
\[a+1=\pm5i\]
\[a=-1\pm5i\]