QuestionChoose the correct term to complete each sentence.
1. Addition and subtraction are examples of ? because they undo each other.
2. An equation that is true for every value of the variable is $\mathrm{a}(\mathrm{n})$ ?.
3. A ratio of two equivalent measures given in different units is a(n) $\qquad$
4. On a map, information such as " $1 \mathrm{in} .: 5 \mathrm{mi}$ " is the ? of the map.
5. In the proportion $\frac{a}{b}=\frac{c}{d}$, $a d$ and $b c$ are the ?.