Question

Simplify according to the given directions.

(12 - 31) + (9 + 21)
1. 3 - 5
2. 21-i
3. 3 - 5
4. 21 +1

Answer 1

The correct answer is option 2, which is 21 - i. The solution is found by separating and then adding the real and imaginary components of the complex expressions given.

Step-by-step explanation:

The correct answer is option 2. The question can be solved using simple rules of addition and subtraction for real and imaginary numbers separately. The given expression is (12 - 31) + (9 + 21). Start by separating the real and imaginary parts of this expression. The real parts are 12 and 9, and the imaginary parts are -31 and +21.

According to the rules for adding numbers with different signs, you subtract the smaller number from the larger number and keep the sign of the larger number. In this case:

Now combine the real and imaginary parts to form a complex number:

21 + (-1)i, or simply 21 - i.