To determine how much silk Amanda has at the end we need to substract the amount each pice need from the original amount:
[tex]\begin{gathered} 25-\frac{18}{7}-\frac{11}{2}-\frac{7}{4}-\frac{25}{7}=25-\frac{43}{7}-\frac{11}{2}-\frac{7}{4} \\ =25-\frac{86+77}{14}-\frac{7}{4} \\ =25-\frac{163}{14}-\frac{7}{4} \\ =25-\frac{652+98}{56} \\ =25-\frac{750}{56} \\ =\frac{1400-750}{56} \\ =\frac{650}{56} \\ =\frac{325}{28} \\ =11\frac{17}{28} \end{gathered}[/tex]Therefore Amanda has 11 17/28 yards of silk left.