294 can be broken down into 7^2 * 6 so √294 it can be written as 7<span>√6 24 can be broken down to 2^2 * 6 so </span>√24 can be written as 2√6 and 54 can be broken down to 3^3 * 6 so √54 can be written as 3√6 then you just add all these together: 7√6 + 2√6 + 3√6 = 12√6 so your answer is D
so: