Best answer:
x²+9= 0
since x = 3i and -3i
(x -3i)(x +3i) =0
Use foil
x² +(3i)x -(3i)x +(3i)(-3i) = 0
3ix and -3ix terms cancel
x² -9i² =0
and since i² = -1
x² +9=0
Best answer: x²+9= 0
since x = 3i and -3i
(x -3i)(x +3i) =0
Use foil
x² +(3i)x -(3i)x +(3i)(-3i) = 0
3ix and -3ix terms cancel
x² -9i² =0
and since i² = -1
x² +9=0