$x:\frac{9}{2}=\frac{1}{3}:\frac{1}{2}$ $\frac{4}{15}:\frac{2}{5}=x:\frac{1}{4}$ $18\times(x - 2)=270$
$\frac{7}{8}x-\frac{3}{4}x=12$ $x - 10\times\frac{4}{5}=1$ $5x+\frac{5}{21}\times3=\frac{5}{7}$
$18:x=4:16$ $\frac{x}{240}=8.4:3.2$ $(x + 25\%)\times80=1000$
$72x - 56x=2880$ $\frac{14}{x}=\frac{10}{9}$ $0.375x+0.5x\times75\%=6$
$\frac{3}{4}:\frac{16}{3}=\frac{1}{8}:x$ $\frac{1}{4}:x=\frac{2}{3}:\frac{1}{6}$ $5:8=\frac{5}{4}:x$

$x = 3$ $x = \frac{1}{6}$ $x = 17$
$x = 96$ $x = 9$ $x = 0$
$x = 72$ $x = 630$ $x = 12.25$
$x = 180$ $x = 12.6$ $x = 8$
$x = \frac{8}{9}$ $x = \frac{1}{16}$ $x = 2$

$\frac{2}{15}\div\frac{4}{35}+\frac{5}{8}$ $4.9\times3.67+4.9\times6.33$ $\frac{11}{12}\times\frac{4}{33}\times9\div\frac{3}{20}$
$\frac{15}{14}-\frac{3}{5}+\frac{13}{14}-\frac{2}{5}$ $(\frac{5}{8}+\frac{2}{27})\times8+\frac{11}{27}$ $2.25\div(4.5 - 4)\div90\%$
$\frac{11}{21}\div\frac{11}{13}+\frac{10}{21}\times\frac{13}{11}$ $(0.63 - 0.63\div3)\times0.5$ $\frac{5}{7}\div[1\div(\frac{2}{3}-25\%)]$
$90\times(\frac{1}{6}+\frac{1}{10}+\frac{1}{15})$ $\frac{5}{6}\times\frac{4}{9}\div\frac{10}{3}+\frac{7}{3}$ $9.6 - 11\div7+\frac{1}{7}\times4$
$2.45\times99\times2+4.9$ $240\div15+2.5\times12$ $12\times[(\frac{11}{6}-\frac{2}{3})\times3]$

$\frac{43}{24}$ $49$ $\frac{20}{3}$
$1$ $6$ $5$
$\frac{13}{11}$ $0.21$ $\frac{25}{84}$
$30$ $\frac{22}{9}$ $8.6$
$490$ $46$ $42$