4^3*4^-5= 4^-2 (add the exponents since the base is the same)
5^-4*5^1= 5^-3 (add the exponents since the base is the same)
Square both terms (double the exponents)
(4^-2)^2= 4^-4
(5^-3)2= 5^-6
Then take out negative exponents (x^-a= 1/x^a)
4^-4 /5^-6 = 5^6/4^4
Final answer: 5^6/4^4
If you want it in number form
5^6= 15625
4^4=256
15625/256= 61.035...