Complex numbers

Question

Determine (a) the sum and (b) the difference of the given complex numbers.

5+8i, 2i

Please explain how to do this.

 

 

Answer 1

With complex numbers, the sum and difference can be found by adding the real and imaginary portions of each number.

 

the sum of the numbers is 

 

5 + 8i + 2i = 5 + 10i

 

The difference is 

 

5 + 8i - 2i = 5 + 6i

Answer 2

 

  5 + 8i + 2i = 5 + 10i

 

  5 + 8i - 2i = 5 + 6i

 

Basically it works just like combining like terms.

 The terms containing the imaginary number i are combined.

 

Answer 3

5 + 8i + 2i = 5 + 10i

5 + 8i - 2i = 5 + 6i

You just treat the i's like a variable and collect like terms.