# College Precal Algrebra

Perform the operation and write the result in standard form.
(√19 + √20i)(√19 – √20i)

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3. 👁 34
1. 19 - 20i

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2. @OOF I tried that. It's saying that it's wrong

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3. i reworked it a bunch of times and i'm stumped. i'm sorry

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4. since (a+b)(a-b) = a^2-b^2
(√19 + √20i)(√19 – √20i)
= 19 - 20i^2 = 19+20 = 39

(a-bi)(a+bi) = a^2+b^2

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👨‍🏫
oobleck

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