What is the value of 12x^-3y^-1 for x=-1 and y=5?
1. -12/5
2. -180
3. -60
4. -5/12
The value of 12x^-3y^-1 when x=-1 and y=5 can be found by substituting these values into the expression.
12(-1)^-3(5)^-1 = 12(-1)^(-3)/5 = 12(-1/(-1)^3)/5 = 12(-1)/5 = -12/5
Therefore, the value of 12x^-3y^-1 for x=-1 and y=5 is -12/5.
Thus, the correct answer is option 1. -12/5.