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anonymous

  • 4 years ago

Simplify the following product of complex numbers.(-3 + 2i) · (-4 – 8i). I got 12-16i is this correct or am I doing something wrong?

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  1. anonymous
    • 4 years ago
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    think there is something wrong here

  2. anonymous
    • 4 years ago
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    ok could you please explain what I am doing wrong oh wait it is 12-16i^2

  3. anonymous
    • 4 years ago
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    \[-3\times -4+2\times 8=28\]

  4. anonymous
    • 4 years ago
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    12-24i-8i+16, 28-32i, or am I being dumb?

  5. anonymous
    • 4 years ago
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    omg I am so confused now

  6. anonymous
    • 4 years ago
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    \[(-3 + 2i) · (-4 – 8i)\] \[(-3\times -4+2\times 8)+(2\times -4-3(-8))i\]

  7. anonymous
    • 4 years ago
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    if that is confusing you can multiply it out just like you would \[(-3 + 2x) · (-4 – 8x)\]

  8. anonymous
    • 4 years ago
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    But remember x^2, i^2 is -1.

  9. anonymous
    • 4 years ago
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    aka first outer inner last \[12 +24i-8i-16i^2\] \[12+16i+16\] \[28+16i\]

  10. anonymous
    • 4 years ago
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    Oh right, I failed to multiply -3 and -8i correctly. Woops. Lol.

  11. anonymous
    • 4 years ago
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    I multiplied -3*-4=12 then got multiplied 2i *8i=16i^2 I am completely conpletely confused feel like an idiot math has never had me so dumb founded

  12. anonymous
    • 4 years ago
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    I get it!!!! I was not solving the whole problem got it THANK YOU THANKYOU SO MUCH!!!!

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