Final answer:
The expression 5/8m + 9 - 3/8m - 15 simplifies to 1/4m - 6 by combining like terms; the terms with 'm' simplify to 1/4m and the constant terms simplify to -6.
Step-by-step explanation:
To simplify the expression 5/8m + 9 - 3/8m - 15, we need to combine like terms. For the variable terms, we have 5/8m and -3/8m. Adding these together, we get (5/8 - 3/8)m, which simplifies to 2/8m or 1/4m. For the constant terms, we have +9 and -15. Adding these together, we get 9 - 15, which simplifies to -6. Therefore, the simplified expression is 1/4m - 6.