Hello from MrBillDoesMath!
Answer:
No real solution.
Complex solutions are x = 3 sqrt(2) i
Discussion:
Real number solutions:
3 and x^2 are both >=0 so their product can not equal -54. No solution
Complex numbers:
3x^2 = -54 => divide both sides by 3
x^2 = - 18 = 9 (-2) => take square roots of both sides
x = 3 sqrt(2) i
where i = sqrt(-1)
Thank you,
MrB