## Introductory Algebra for College Students (7th Edition)

a. Natural: $\sqrt{100}$ b. Whole: $0,\sqrt{100}$ c. Integer: $-9,0,\sqrt{100}$ d. Rational: $-9,-\displaystyle \frac{4}{5},0.25,9.2,\sqrt{100}$ e. Irrational: $\sqrt{3}$ f. Real: all of them
The set of natural numbers is { 1, 2, 3, 4, 5, ... } . The set of whole numbers is { 0, 1, 2, 3, 4, 5, ... } The set of integers is {... , -4, -3, -2, -1,0, 1, 2, 3, 4,...} The set of rational numbers$: \displaystyle \frac{a}{b},\ b\neq 0$, and b integers Irrational numbers: are not rational (can not be written as $\displaystyle \frac{a}{b},\ b\neq 0$) Real numbers: all rational and irrational numbers. --- $-9$ is a negative integer, can be written as $\displaystyle \frac{-9}{1}$ so is also rational $-\displaystyle \frac{4}{5}$ is a rational number $0$ is a whole number, an integer, rational ($\dfrac 01$) $0.25=\displaystyle \frac{25}{100}$ is a rational number $\sqrt{3 }$ is irrational $9.2=\displaystyle \frac{92}{10}$ , rational $\sqrt{100}=10,$ natural, whole, integer, rational. a. Natural: $\sqrt{100}$ b. Whole: $0,\sqrt{100}$ c. Integer: $-9,0,\sqrt{100}$ d. Rational: $-9,-\displaystyle \frac{4}{5},0.25,9.2,\sqrt{100}$ e. Irrational: $\sqrt{3}$ f. Real: all of them