Complex Number?

2 ⤊

what is (-3 +7i) (1 - 2i) as a complex number in standard form

2007-05-10 10:26:20 · 4 answers · asked by Paul S 1 in Science & Mathematics ➔ Mathematics

just open parenthesis

(-3 +7i) (1 - 2i) =
-3 + 7i + 6i - 14i^2 =
-3 + 7i + 6i + 14 =
11 + 13i

2007-05-10 10:30:11 · answer #1 · answered by iluxa 5 · 2⤊ 0⤋

-3*1 +6i +7i +14 = 11 +13i

2007-05-10 17:32:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋

(-3)(1)+(-3)(-2i)+(7i)(1)+(7i)(-2i)
-3 + 6i +7i -14i^2
-3 + 13i -14(-1)
11+13i

2007-05-10 17:31:24 · answer #3 · answered by hawkeye3772 4 · 0⤊ 0⤋

Just multiply it out the same as you would any other polynomial, collect the terms, and remember that iÂ² = -1.

HTH

Doug

2007-05-10 17:34:16 · answer #4 · answered by doug_donaghue 7 · 0⤊ 0⤋