Solve the question by completing the square: 5x^2 - 4 = -8

Question

Solve the question by completing the square: 5x^2 - 4 = -8

Answer 1

5x^2 -4=-8

5x^2 = -4

x^2 = -4/5

x = +/-2i/sqr5

x = +/-2i(sqr5)/5

UNLESS maybe the problem really was intended to read

5x^2 -4x =-8,

then

5(x^2-4x/5 + 4/25) = -8 +4/5

5(x-2/5)^2 = -36/5

x-= .4 +/-isqr(36/25)

= (2 +/-6i)/5