Final answer:
To rewrite the expression, break down each place value and simplify.
Step-by-step explanation:
To rewrite the expression, we need to break up each of the place values.
70 + _____ + _____ + (-30) + (-9) + (_____)
The expression can be broken down as follows:
70 + (0) + (0) + (-30) + (-9) + (0)
Simplifying, we get: 70 - 30 - 9
Therefore, the correct answer is a) 60 - 30 - 9.