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Sinz
Group Title
Simplify the following quotient of complex numbers into the form a + bi. 9+8i/1+2i
 3 years ago
 3 years ago
Sinz Group Title
Simplify the following quotient of complex numbers into the form a + bi. 9+8i/1+2i
 3 years ago
 3 years ago

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Walleye Group TitleBest ResponseYou've already chosen the best response.0
You going to mutiply the numorator and the denominatior by the conjugate. Does that help?
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
so multiply 9 and 1 right
 3 years ago

jimmyrep Group TitleBest ResponseYou've already chosen the best response.2
multiply top and bottom of the quotient by the conjugate of 1 + 2i which is 1  2i
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
huh I am confused
 3 years ago

Walleye Group TitleBest ResponseYou've already chosen the best response.0
Your goal here is to "kill" the bottom complex number. you can do this by \[(9+8i/1+2i) * (1  2i / 1  2i)\] remember that 12i / 12i = 1 and you can multiply anything by 1
 3 years ago

Walleye Group TitleBest ResponseYou've already chosen the best response.0
without changing the number
 3 years ago

jimmyrep Group TitleBest ResponseYou've already chosen the best response.2
(9 + 8i)(12i)  (1+2i)(12i) the denominator simplifies to 1 + 4 = 5
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
so I take and combine like terms right?
 3 years ago

Walleye Group TitleBest ResponseYou've already chosen the best response.0
yep. you'll find that if you multiply a complex number by its conjugate then you kill all of the i terms and just be left with real numbers
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
after I get the )9+8i)(12i)
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
so it will be 9*1 and 8i*2i?
 3 years ago

jimmyrep Group TitleBest ResponseYou've already chosen the best response.2
yes  u now simplify the top expression then divide by 5
 3 years ago

jimmyrep Group TitleBest ResponseYou've already chosen the best response.2
no remember (a+b)(a+b) = a^2 + 2ab + b^2
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
so 9  16i/5 is what it should look like right
 3 years ago

Walleye Group TitleBest ResponseYou've already chosen the best response.0
nope. your top term is off. Try using FOIL on the top again and see if you get somthing else.
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
okay lemme see (9+8i)(12i) combine like terms 9*1=9 8i*2i=16i total is 9+16i/5 is that right
 3 years ago

jimmyrep Group TitleBest ResponseYou've already chosen the best response.2
(9 + 8i)(12i) = 9 + 18i + 8i + 16 = 7 + 26i the second bracket is first multiplied by 9 then its multuplied by + 81
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
oh okay wasn't seeing how it was done that is why I was confuzzled
 3 years ago

Walleye Group TitleBest ResponseYou've already chosen the best response.0
I dont know if this will help but treat i just like you would x when your distributing! I find that thinking about it that way very helpfful
 3 years ago

jimmyrep Group TitleBest ResponseYou've already chosen the best response.2
final result is 7/5 + (26/5) i
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
okay so in algebra they try to change things up so it confuses you?
 3 years ago

Sinz Group TitleBest ResponseYou've already chosen the best response.0
Thank you Jimmy you was very helpful as was you Walleye
 3 years ago
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