2006-12-16 11:30:12 · 8 answers · asked by hans d 1 in Science & Mathematics ➔ Mathematics
First: use distribution by multiplying -2i to everything inside the parenthesis:
(-2i)(5) - (4i)(-2i)
= -10i + 8i^2
Second: the rule is i^2 is -1 and replace i^2 with -1
= -10i +8(-1)
= -10i - 8
2006-12-16 14:03:19 · answer #1 · answered by ♪♥Annie♥♪ 6 · 0⤊ 0⤋
-2i(5-4i)=
-10i + 8i^2
Since i^2 = -2, 8i^2 = -8
Rewriting in standard form,
-8 - 10i
2006-12-16 19:32:51 · answer #2 · answered by Joni DaNerd 6 · 1⤊ 1⤋
2i(5-4i)=10i-8i^2=10i+8=8+10i
2006-12-16 21:48:56 · answer #3 · answered by yupchagee 7 · 0⤊ 1⤋
-10i +2
2006-12-16 19:31:35 · answer #4 · answered by Alan Turing 5 · 0⤊ 1⤋
-2i(5-4i)
10i+8i^2
10i+8(-1)
10i-8
-8+10i
2006-12-16 19:35:15 · answer #5 · answered by NAchik09 2 · 0⤊ 2⤋
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2006-12-16 19:33:00 · answer #6 · answered by lori b 2 · 0⤊ 0⤋
-10i+8i*i=-10i-8
2006-12-16 19:39:17 · answer #7 · answered by catty 1 · 1⤊ 0⤋
-10i-8
-8-10i
2006-12-16 19:35:42 · answer #8 · answered by raj 7 · 1⤊ 0⤋