Simplest form 9/10 - 3/4

Solution:
1. Identify the fractions:
- First fraction: \frac{9}{10}
- Second fraction: \frac{3}{4}

2. Find the least common denominator (LCD) of the fractions:
- The denominators are 10 and 4.
- The least common denominator is 20.

3. Convert each fraction to have the LCD:
- Convert \frac{9}{10}:
\frac{9}{10} = \frac{9 \times 2}{10 \times 2} = \frac{18}{20}
- Convert \frac{3}{4}:
\frac{3}{4} = \frac{3 \times 5}{4 \times 5} = \frac{15}{20}

4. Subtract the fractions with the same denominator:
\frac{18}{20} - \frac{15}{20} = \frac{18 - 15}{20} = \frac{3}{20}

5. The simplest form of the expression is:
\frac{3}{20}