So, for #1, we can just simplify 3(2x - 5) to get another expression:
3(2x - 5),
6x-15
For the next one, we could make a new equation that equals 6x-15:
(3x)+(3x)+(5 *-3)
Then for the last one, how about rewrite it so all of the values are inversely negated?
3(2x - 5),
-3(-2x +5)