Answer:
[tex] \frac{1}{15} x[/tex]
Step-by-step explanation:
[tex] \frac{7x}{20} - \frac{5x}{12} [/tex]
[tex] \frac{3 \times 7x}{3 \times 20} - \frac{5 \times 5x}{5 \times 12} [/tex]
[tex] \frac{21x}{60} - \frac{25x}{60} [/tex]
[tex] \frac{21x - 25x}{60} = (21 - 25)x = - 4x[/tex]
[tex] \frac{ - 4x}{60} = - \frac{ x}{15} [/tex]
[tex]\boxed{\green{= \frac{1}{15} x}}[/tex]