24 4/5 - 19,5; 7 2/9

To prepare for university exams, it is important to practice working with different types of numbers, such as mixed numbers and fraction subtraction. Let's solve the given expression step-by-step:

First, let's convert the mixed numbers to improper fractions:

24 4/5 = (24 * 5 + 4) / 5 = 124/5 7 2/9 = (7 * 9 + 2) / 9 = 65/9

Now, subtract the fractions: 124/5 - 65/9

To subtract fractions, we need a common denominator. The least common multiple (LCM) of 5 and 9 is 45.

Multiply the numerator and denominator of the first fraction by 9, and the numerator and denominator of the second fraction by 5:

(124 * 9) / (5 * 9) - (65 * 5) / (9 * 5) = 1116/45 - 325/45

Now that the fractions have a common denominator, subtract the numerators:

1116/45 - 325/45 = (1116 - 325) / 45 = 791/45

The result is 791/45.