Question

For what real number k does the product (25 + ki)*(3+2i) equal a real number?

Answer 1

(25 + ki)*(3+2i) = 75+3ki+50i-2k
= 75-2k + (3k+50)i

So, you need 3k+50 = 0, since real numbers have zero imaginary part.

Answer 2

are you sure? I need the actual answer.

Answer 3

well, geez. You cant solve 3k+50 = 0?

k = -50/3

(25 - 50/3 i)*(3+2i) = 325/3

which is a real number

Answer 4

Uhh 325/3 isn't right

Answer 5

Um, Lelface the answer isnt 325/3. It's -50/3, like steve said earlier. He was just substituting the answer in to show it worked.

Answer 6

it's -50/3