1. 填空。
$(\frac{7}{18}+\frac{5}{12})×36=$×+×
$\frac{16}{23}×\frac{7}{15}+\frac{8}{15}×\frac{16}{23}=(\_\_\_\_\_\_)×$

$(\dfrac{7}{18}+\dfrac{5}{12})×36=\underline{\dfrac{7}{18}}×\underline{36}+\underline{\dfrac{5}{12}}×\underline{36}$
$\dfrac{16}{23}×\dfrac{7}{15}+\dfrac{8}{15}×\dfrac{16}{23}=(\underline{\dfrac{7}{15}}+\underline{\dfrac{8}{15}})×\underline{\dfrac{16}{23}}$

2. 计算下面各题,能用简便算法的就用简便算法。
$\frac{3}{7}×\frac{2}{13}×14×26$
$(\frac{4}{5}-\frac{2}{3})×15$
$\frac{17}{27}×\frac{13}{17}+\frac{13}{17}×\frac{10}{27}$
$\frac{15}{33}×16+18×\frac{15}{33}-\frac{15}{33}$

$\frac{3}{7}×\frac{2}{13}×14×26$
$=(\frac{3}{7}×14)×(\frac{2}{13}×26)$
$=6×4$
$=24$
$(\frac{4}{5}-\frac{2}{3})×15$
$=\frac{4}{5}×15-\frac{2}{3}×15$
$=12-10$
$=2$
$\frac{17}{27}×\frac{13}{17}+\frac{13}{17}×\frac{10}{27}$
$=\frac{13}{17}×(\frac{17}{27}+\frac{10}{27})$
$=\frac{13}{17}×1$
$=\frac{13}{17}$
$\frac{15}{33}×16+18×\frac{15}{33}-\frac{15}{33}$
$=\frac{15}{33}×(16+18-1)$
$=\frac{15}{33}×33$
$=15$

用简便方法计算下面各题。
$2026×\frac{2026}{2027}$
$13×(\frac{1}{13}+\frac{3}{17})×17$
$77×\frac{75}{76}$
$71×\frac{25}{44}+25×\frac{17}{44}$

$2026×\frac{2026}{2027}$
$=(2027-1)×\frac{2026}{2027}$
$=2027×\frac{2026}{2027} - 1×\frac{2026}{2027}$
$=2026 - \frac{2026}{2027}$
$=2025\frac{1}{2027}$
$13×(\frac{1}{13}+\frac{3}{17})×17$
$=13×\frac{1}{13}×17 + 13×\frac{3}{17}×17$
$=17 + 39$
$=56$
$77×\frac{75}{76}$
$=(76+1)×\frac{75}{76}$
$=76×\frac{75}{76} + 1×\frac{75}{76}$
$=75 + \frac{75}{76}$
$=75\frac{75}{76}$
$71×\frac{25}{44}+25×\frac{17}{44}$
$=71×\frac{25}{44} + 17×\frac{25}{44}$
$=(71+17)×\frac{25}{44}$
$=88×\frac{25}{44}$
$=50$