Question

Write
`√(64) - √(-289)` as a complex number in the form of a + bi.

A. -17 - 8i

B. 8 + 17i

C. 8 - 17i

D. 17 + 8i

Answer 1

since if you simplify you would get 8 as the first term so that could only leave 2 possibilities and you can see that the negative in the -289 would be i so the only possible answer is C

Answer 2

C

Explanation:

So we have:

`√(64)-√(-289)`

First, separate out a -1 from the second term:

`=√(64)-√(289\cdot -1)\\=√(64)-√(-1)(√(289))`

Change the square root of -1 to i:

`=√(64)-i√(289)`

The square root of 64 is 8.

And the square root of 289 is 17. Simplify:

`=8-17i`

So, our answer is C.

And we're done :)