15-64:(-8)

It seems like you're presenting an equation or a mathematical expression. The expression "15 - 64 - 8" can be simplified.

1. Start with the expression: 15 - 64 - 8
2. First, subtract 64 from 15:
   • \(15 - 64 = -49\)
3. Then subtract 8 from -49:
   • \(-49 - 8 = -57\)

So, 15 - 64 - 8 = -57. If you meant something different or need further clarification, please let me know!