Question

Write V-16 + V49 as a complex number in the form of a + bi.

A. 7 + 4i
B. 7-41
C.-4+ 71
D.
4 + 71
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Answer 1

A. 7 + 4i

Explanation:

`\text{Use:}\\\\i=√(-1)\\\\√(ab)=√(a)\cdot√(b)\\\\√(a)=b\iff b^2=a\\\\=========================`

`√(-16)+√(49)=4i+7=7+4i\\\\\text{because}\\\\√(49)=7\ \text{because}\ 7^2=49\\\\√(-16)=√((16)(-1))=√(16)\cdot√(-1)=4i\qquad /√(16)=4\ \text{because}\ 4^2=16/`