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Show all work to multiply

Show all work to multiply-example-1

1 Answer

5 votes

Answer:

-42+10i

Explanation:

*start with the square roots

\sqrt{-25} \\ =5i

\sqrt{-100} \\ = 10i

*then insert values

(2+5i)(4-10i)

*Use FOIL to multiply

2x4 + 2x-10i + 5ix4 + 5ix10i

*Simplify

8-10i+20i+50i(squared)

*Add like terms

-42+10i

*( i squared = -1 )

User Marsbear
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