Final answer:
The difference between 3.3 and -1.3 can be represented as the expression 3.3 - (-1.3). To simplify this expression, we need to add the positive equivalent of the negative number. Therefore, the simplified expression is 3.3 + 1.3.
Step-by-step explanation:
To translate the given phrase into mathematical language, we can represent the difference between 3.3 and -1.3 as a subtraction operation. The numerical expression for the phrase is 3.3 - (-1.3). To simplify the expression, we need to subtract a negative number, which is the same as adding the positive equivalent. So, 3.3 - (-1.3) becomes 3.3 + 1.3. Therefore, option b) 3.3 + 1.3 is the simplified expression.