Answer
a. $\sqrt {81}=9$
b. $0,\sqrt {81}=9$
c. $-17, 0,\sqrt {81}=9$
d. $-17, -\frac{9}{13}, 0, 0.75,\sqrt {81}=9$
e. $\sqrt 2, \pi$
f. all numbers from the list.
Work Step by Step
a. natural numbers are whole numbers excluding zero, thus we have $\sqrt {81}=9$ as a natural number from the list.
b. whole numbers are positive integers including zero; thus we have $0,\sqrt {81}=9$ as whole numbers from the list.
c. integers include both positive and negative whole numbers; thus we have $-17, 0,\sqrt {81}=9$ as integers from the list.
d. rational numbers are numbers that can be expressed as the ratio of integers (excluding zero in the denominator); thus we have $-17, -\frac{9}{13}, 0, 0.75,\sqrt {81}=9$ as rational numbers from the list.
e. irrational numbers are real numbers excluding rational numbers, thus we have $\sqrt 2, \pi$ as irrational numbers from the list.
f. real numbers: all numbers from the list are real numbers.
