# Three times the total number of adults was 17 less than the number of children who visited the petting zoo. How do you write an equation to model this relationship?

Oct 27, 2016

$c = 3 a + 17$

#### Explanation:

We do not know how many people altogether visited the zoo, but we do know the relationship between the numbers.

There were obviously many more children than adults. The number of adults, multiplied by 3 is still less than the number of children!

Let the number of adults be $a$ and the number of children be $c$

$c = 3 a + 17$

This can also be written as:

$3 a = c - 17$

Or: $c - 3 a = 17$

Or: $a = \frac{c - 17}{3}$