Question #e5914

Mar 30, 2016

Rational

Explanation:

Rational numbers are characterized as numbers that can be expressed by $\frac{p}{q}$. In order for a number to be rational, it must have the ability to be expressed as a fraction.

Rational examples: $\sqrt{4}$, $2.7$, $128$, $- 36$
Irrational examples: $\sqrt{2}$, $\sqrt{7}$, $\pi$

$- 4.2$ can be expressed as the fraction $\frac{- 21}{5}$
Therefore it is rational.