Question

classify the numbers as rational or irrational.
9 -4 9 + -4
rational irrational

Explanation:

Step1: Recall rational number definition

A rational number is a number that can be expressed as $\frac{p}{q}$ where $p$ and $q$ are integers and $q
eq0$. Integers, fractions, terminating decimals, repeating decimals are rational. Irrational numbers cannot be expressed as such (e.g., $\sqrt{2}$, $\pi$).

Step2: Classify 9

9 is an integer. Integers can be written as $\frac{9}{1}$ (where $p = 9$, $q=1$ are integers, $q
eq0$). So 9 is rational.

Step3: Classify -4

-4 is an integer. Integers can be written as $\frac{-4}{1}$ (where $p=-4$, $q = 1$ are integers, $q
eq0$). So -4 is rational.

Step4: Classify $9 + (-4)$

First, calculate $9+(-4)=9 - 4=5$. 5 is an integer, which can be written as $\frac{5}{1}$ (where $p = 5$, $q=1$ are integers, $q
eq0$). So $9+(-4)$ is rational.

Step5: Check for irrational numbers

None of the given numbers (9, -4, $9+(-4)$) are irrational (since they are all integers, hence rational). So the irrational box remains empty.

Answer:

rational: 9, -4, $9 + -4$
irrational: (empty)