[a√(1/a)+√(4b)]-[√a/2-b√(1/b)]
=[√a^2(1/a)+√(4b)]-[√a/2-√b^2(1/b)]
=[√a+2√b]-[√a/2-√b]
=√a+2√b-√a/2+√b
=√a/2+3√b