[tex]12 \frac{1 \times 4}{3 \times 4} - 10 \frac{3 \times 3}{4 \times 3} = 12 \frac{4}{12} - 10 \frac{9}{12} = 11 \frac{16}{12} - 10 \frac{9}{12} = 1 \frac{7}{12} [/tex]
