How do you multiply #(3-5i)(3+5i)#?

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Answer 1 · 2018-05-25T20:47:57

Answer: #34#

Note that the expression is in the difference of squares pattern #(a-b)(a+b)#, which is equal to #a^2-b^2#

By applying this formula, we have:

#(3-5i)(3+5i)=3^2-(5i)^2#

#=9-5^2*i^2#

Noting that #i^2=-1#,

#=9-(-25)#

#=9+25#

#=34#