Question 164695
when you cube the 1st term out you get (4^-6*x^3*y^-9/x^-9*y^3)  the second term invert and square you get (x^8*y^-2/8^-2*x^-4*y^2)  when you switch 8^-2 to the numerator you have 8^2 or 8squared and when you switch 4^-6 to the denominator you get 4^6 or 4*4*4*4*4*4  when you simplify 8^2/4^6 you get 1/64....that is where the 64 comes into play in the answer....