1x + 1x - 4x 5 12 3

To simplify the expression \( \frac{1x}{5} + \frac{1x}{12} - \frac{4x}{3} \), we should first find a common denominator.

The denominators are 5, 12, and 3. The least common multiple (LCM) of these numbers is 60.

Now, we will rewrite each term with the common denominator of 60:

1. For \( \frac{1x}{5} \): \[ \frac{1x}{5} = \frac{1x \cdot 12}{5 \cdot 12} = \frac{12x}{60} \]

2. For \( \frac{1x}{12} \): \[ \frac{1x}{12} = \frac{1x \cdot 5}{12 \cdot 5} = \frac{5x}{60} \]

3. For \( \frac{4x}{3} \): \[ \frac{4x}{3} = \frac{4x \cdot 20}{3 \cdot 20} = \frac{80x}{60} \]

Now, substituting these back into the expression, we get:

\[ \frac{12x}{60} + \frac{5x}{60} - \frac{80x}{60} \]

Now combine the fractions:

\[ \frac{12x + 5x - 80x}{60} = \frac{(12 + 5 - 80)x}{60} = \frac{-63x}{60} \]

So, the simplified expression is:

\[ -\frac{63x}{60} \]

This can also be written as:

\[ -\frac{21x}{20} \]

So the final answer is:

\[ -\frac{21x}{20} \]