Давай разберемся с этим примером по шагам:
\[ \frac{7}{4} = \frac{7 \times 3}{4 \times 3} = \frac{21}{12} \]
\[ \frac{2}{3} = \frac{2 \times 4}{3 \times 4} = \frac{8}{12} \]
\[ \frac{8}{4} = \frac{8 \times 3}{4 \times 3} = \frac{24}{12} \]
\[ \frac{21}{12} - \frac{8}{12} + \frac{24}{12} = \frac{21 - 8 + 24}{12} = \frac{13 + 24}{12} = \frac{37}{12} \]
\[ \frac{37}{12} = 3 \frac{1}{12} \]
Ответ:
\[ \frac{37}{12} \] или \[ 3 \frac{1}{12} \]