1) √3(2)-2/3^2 = √6-2/9= 2/9
As you see, as according to the rule, 3 would be represented by the variable a while 2 would be represented by the variable b. Since you know this, you simply plug the values into the equation, plugging 3 in where a belongs and plugging 2 in where b belongs. After this, you simplify which gets you to your answer, 2/9.
2.)3(ab^2)^3= 3(a^3b^2*3)=3(a^3 b^6)= 3a^3b^6
Since you know the rule of indices or indexes (the power) in this case would be distributing the outside exponent, 3 to the inner exponents a^1(since there is no power labeled, it is implied that a is raised to the first power) b^2, which would be multiplying the outside exponent to the inner indexes. Then, once you have done this, you distribute the value, 3, to a^3b^6.