(((3у+1)/(5-4х))^-3)*(((4x-5)/(1+3y))^-4

(((3у+1)/(5-4х))^-3)*(((4x-5)/(1+3y))^-4 = (((5-4x)/(3y+1))^3)*(((1+3y)/(4x-5))^4 =  = (5-4x)^3 * (1+3y)^4 / ((5-4x)^4 * (1+3y)^3)= (1+3y)/(5-4x) (a-b)^4=(b-a)^4