Question

For i = √−1 , what is the sum (7 + i) + (−8 + 9i ) ? √ is the square root symbol.

A) −1 + 12i
B) −1 − 6i
C) 15 + 12i
D) 15 − 6i

Answer 1

Question is incomplete, complete question is given below;

For i = √−1 , what is the sum (7 + 3i) + (−8 + 9i ) ? √ is the square root symbol.

Answer:

A) −1 + 12i

Explanation:

Given,

`i = √(-1 )`

We have to find the sum of
`(7+3i)+(-8+9i)`.

Solution,

Firstly we Substitute the the value of 'i' in given expression.

`(7 + 3√(-1)) + (-8 + 9√(-1) )`

On combining the like terms, we get;

`7+(-8)+3√(-1)+9√(-1)`

On we use the addition property of equality and get;

`-1+12√(-1)`

Since
`√(-1)` = i

Then we can say that;

`-1+12√(-1)` =
`-1+12i`

Hence The sum of
`(7+3i)+(-8+9i)` is
`-1+12i`.