math
posted by girl .
simplify
sixth squareroot of 27a6b3 + 7a eight squareroot of 81b4?
please help me

did you mean
(27a^6b^3)^(1/6) + 7a(81b^4)^(1/8) ??
then...
= [(3^3)(a^6)(b^3)]^(1/6) + 7a[(3^4)(b^4)]^(1/8)
=(3^(1/2)(a)(b)^(1/2) + 7a(3^(1/2))(b^(1/2))
= 8a√(3b)