1) =(2^3*5^6)^1/3=2*5^2=2*25=50
2) = (a^6*b^7)^1/5 : (ab^2)^1/5=a^6/5*b^7/5 : a^1/5*b^2/5=a^5/5*b^5/5=ab
1) = (3^12*(1/3)^8)^1/4=3^3*(1/3)^2=27*1/9=3
2) = (81x^4y)^1/3 : (3xy)^1/3=(3^4*x^4*y)^1/3 : 3^1/3*x^1/3*y^1/3 = 3^4/3*x^4/3*y^4/3 : 3^1/3*x^1/3*y^1/3=3xy