## College Algebra 7th Edition

(a) $100$ (b) $0, 100, -8$ (c) $-1.5, 0, 5/2, 2.71, 3.1\bar4, 100, -8$ (d) $\sqrt7, -\pi$
(a) Natural numbers are positive integers, so only 100 qualifies. (b) Integers are positive or negative whole numbers and zero, so 0, 100, and -8 qualify. (c) Rational numbers are those that can be expressed as a ratio of integers. -1.5=-3/2, so it qualifies. 0=0/1, so it qualifies. 5/2 is a ratio of integers, so it qualifies. 2.71=271/100, so it qualifies. $3.1\bar4$=283/90, so it qualifies. 100=100/1, so it qualifies. -8=-8/1, so it qualifies. (d) Irrational numbers can not be expressed as ratios of integers, so $\sqrt7$ and -$\pi$ qualify.