Final answer:
The expressions are rewritten using only addition by turning each number that was being subtracted into its negative counterpart and then adding it. For A) a + b - c + d + 6 becomes a + b + (-c) + d + 6, and for B) -a - b - 4 - (8/7)z becomes (-a) + (-b) + (-4) + (-(8/7)z).
Step-by-step explanation:
To write each expression using only addition, we need to convert the subtraction into addition by changing the sign of the number that comes after the subtraction sign. This is based on the rule that subtracting a number is the same as adding its opposite. Here are the equivalent expressions using only addition:
- A) a + b - c + d + 6 becomes a + b + (-c) + d + 6
- B) -a - b - 4 - (8/7)z becomes (-a) + (-b) + (-4) + (-(8/7)z)
In each case, the subtraction sign in front of a number has been replaced with an addition sign in front of the negative of that number.
By converting subtractions to additions of negative numbers, we retain the same numerical value for the expressions.