Lucinda uses properties of operations to write an expression equivalaent to 9 + 3 (5 - a) - 7a. Which could be the expression that Lucinda wrote?

A. 60 - 19a
B. 24 - 8a
C. 24 - 10a
D. 24 - 4a

1 answer

To simplify the expression, we can start by distributing the 3 to both the 5 and the -a:

9 + 3(5 - a) - 7a = 9 + 15 - 3a - 7a

Next, we can combine like terms:

9 + 15 - 3a - 7a = 24 - 10a

Therefore, the expression that Lucinda wrote is 24 - 10a.

The correct answer is C. 24 - 10a.