Explanation:
When we simplify the expression -5/9 - (-9/4), we can rewrite it as:
-5/9 + 9/4
To add these fractions, we need to find a common denominator. The least common multiple of 9 and 4 is 36, so we can convert both fractions to have a denominator of 36:
-5/9 = -20/36
9/4 = 81/36
Now we can substitute these values into our expression and add them:
-20/36 + 81/36 = 61/36
Therefore, the simplified expression is 61/36.