Question

Rationalize the denominator of square root of negative 49 over open parentheses 7 minus 2 i close parentheses minus open parentheses 4 plus 9 i.

Answer 1

sqrt(-49) / [ (7-2i) - (4+9i) ]

= 7i / (3 - 11i)

= 7i (3+11i) / [ (3 - 11i) (3 + 11i) ]

= (21 i - 77) / (9 + 121) = choice (d), (-77 + 21i) / 130