Note that the LCD is 15. Both 5 and 3 divide evenly into 15.
Thus, the expression can be rewritten as -12 6/15 - 6 10/15.
This is actually a problem in addition, because there are two " - " signs.
Rewrite -12 6/15 - 6 10/15 vertically:
-12 6/15
- 6 10/15
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-18 16/15, or -19 1/15 (answer)
