Question 105284
I MUST APPOLOGIZE FOR INCORRECT DATA. iT WAS LATE & I WASN'T THINKING STRAIGHT.
WHEN YOU RAISE POWERS BY POWERS YOU NEED TO MULTIPLY THE POWERS.
THUS (M^4)^-3=M^(4*-3)=M^-12 
(M^-2)^4=M^(-2*4)=M^-8  
NOW WE HAVE:
M^-12/M^-8
1/M^12*M^8
M^8/M^12
M^(8-12)=M^-4 OR 1/M^4