Final answer:
The value of the expression 12.3 - (-21.45) is 33.75. This is calculated by changing the subtraction of the negative number to the addition of its positive equivalent and then adding it to 12.3.
Step-by-step explanation:
The value of the expression 12.3 - (-21.45) is obtained by changing the subtraction of a negative number into the addition of a positive number. So, the expression can be rewritten as 12.3 + 21.45. Adding the two numbers gives us 33.75. Hence, the value of the expression is 33.75.
Here is the step by step solution:
- Change the subtraction of a negative number to addition: 12.3 - (-21.45) = 12.3 + 21.45
- Add the numbers: 12.3 + 21.45 = 33.75
Note that when you subtract a negative number, it's the same as adding the positive equivalent of that number.