(-3 - 2i)(-3 + 3i)
2007-03-08 14:21:14 · 4 answers · asked by Help please 1 in Science & Mathematics ➔ Mathematics
9-9i+6i+6
15-3i
2007-03-08 14:24:33 · answer #1 · answered by bruinfan 7 · 0⤊ 1⤋
It's just like multiplying any binomial expressions: multiply each element in the first binomial with each element in the second....
(-3 * -3) + (-3 * 3i) - (2i * -3) - (2i * 3i)
You group the results together, remembering that i*i = -1, until you get an answer that looks like (a + bi).
2007-03-08 14:27:41 · answer #2 · answered by Rando 4 · 0⤊ 0⤋
You can multiply this algebraically. i = sqrt(-1), i*i = -1
(-3 - 2i)(-3 + 3i) = 9 - 9i + 6i + 6 = 15 - 3i
2007-03-08 14:26:05 · answer #3 · answered by milamtil 2 · 0⤊ 0⤋
Use the previous FOIL trick: First, outdoors, interior, final (3-i)(-6+i)= 18(F) +3i(O) +6i(I) -i^2(L) =18 +9i +a million =19 + 9i The frustrating area is -i^2. Write this as -a million(i^2) i=rt(-a million), so i^2 is (rt-a million)(rt-a million), that's -a million. We for this reason get -a million(-a million), =+a million
2016-11-23 16:30:02 · answer #4 · answered by fulgham 4 · 0⤊ 0⤋