lucinda uses the properties of operations to write an expression equivalent to 9 plus 3 (5- a) - 7a
Lucinda can use the distributive property to expand the expression as follows:
9 + 3(5 - a) - 7a
= 9 + 3 * 5 - 3 * a - 7a
= 9 + 15 - 3a - 7a
= 24 - 10a
Therefore, the expression equivalent to 9 + 3(5 - a) - 7a is 24 - 10a.