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28 votes
28 votes
Perform the indicated operation and write the answer in the form a + bi.
(3 +81) (4-3i)

User Kraken
by
2.9k points

2 Answers

24 votes
24 votes

SOLVING


\Large\maltese\underline{\textsf{A. What is Asked \space}}

Perform the indicated operation and write the answer with the form a+bi.

2 numbers given, one of which is complex


\Large\maltese\underline{\textsf{B. This problem has been solved!\space\space}}

Multiply these two numbers, just like you always multiply binomials.


\bf{(3+8i)(4-3i)} | multiply


\bf{3*4+3*(-3i)+8i*4+8i*(-3i)} | simplify


\bf{12-9i+32i-24i^2} | this can be simplified A LOT


\bf{12+23i-24i^2} | as strange as it may seem, this can be simplified even more, because isn't i^2 the same as -1?


\bf{12+23i-24*(-1)}=12+23i+24} | add 12 and 24


\bf{36+23i}


\rule{300}{1.7}


\bf{Result:}


\bf{=36+23i}. The answer is written in the form a+bi, as requested.


\boxed{\bf{aesthetic\\ot101}}

User Rschlachter
by
3.0k points
8 votes
8 votes


\quad \huge \quad \quad \boxed{ \tt \:Answer }


\qquad \tt \rightarrow \: 36 + 23 i

____________________________________


\large \tt Solution \: :


\qquad \tt \rightarrow \: (3 + 8i)(4 - 3i)


\qquad \tt \rightarrow \: (3 \sdot 4)+ (3 \sdot - 3i) + (8i \sdot4) + (8i \sdot - 3i)


\qquad \tt \rightarrow \: 12 - 9i + 32i - (24 {i}^(2) )


\qquad \tt \rightarrow \: 12 + 23i -( 24 \sdot - 1)


\qquad \tt \rightarrow \: 12 + 23i + 24


\qquad \tt \rightarrow \: 36 + 23i

Answered by : ❝ AǫᴜᴀWɪᴢ ❞

User Ducminh
by
2.7k points