a Any sum or product that is rational can be rewritten as a fraction ab, where a and b are integers. Notice that 5 is not a perfect square such as 4, 9 or 16, which means it will have infinite non-repeating decimals. Therefore, this is an irrational number.
b Let's simplify the expression by adding the fractions.
Since we were able to rewrite the sum as a fraction ab where a and b are integers, this is a rational number.
c Like in Part A, we have a square root where the radicand is not a perfect square. Therefore, this must be an irrational number.
d Notice that 9 is a perfect square as 3^2=9. However, it is not a perfect cube. The factor sqrt(9) will have infinite non-repeating decimals and therefore, this is an irrational number.
