Question

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Answer 1

50

Explanation:

`i=√(-1)\to i^2=-1\\\\(3+√(-16))(6-√(-64))\\\\√(-16)=√((16)(-1))=√(16)\cdot√(-1)=4i\\√(-64)=√((64)(-1))=√(64)\cdot√(-1)=8i\\\\(3+4i)(6-8i)\\\\\text{use FOIL}\ (a+b)(c+d)=ab+ac+bc+bd\\\\=(3)(6)+(3)(-8i)+(4i)(6)+(4i)(-8i)\\\\=18-24i+24i-32i^2\qquad\text{cancel}\ 24i\\\\=18-32(-1)=18+32=50`