1. 直接写出得数。（4分）
$\frac{5}{8} - \frac{3}{8} =$
$\frac{3}{4} + \frac{2}{3} =$
$1 - \frac{4}{13} + \frac{9}{13} =$
$(121, 88) =$
$\frac{1}{4} - \frac{1}{9} =$
$\frac{17}{39} × 78 =$
$\frac{5}{8} + \frac{1}{4} + \frac{3}{8} - \frac{1}{4} =$
$[12, 18] =$

1.$\frac{1}{4}$ $\frac{17}{12}$ $\frac{18}{13}$ 11 $\frac{5}{36}$ 34 1 36

2. 解方程。（6分）
$x+\dfrac{2}{3}=1$
$2.5x - 0.5× 8=12$
$2.4x + 3.8x=93$

2.$x=\frac{1}{3}$ $x=6.4$ $x=15$

$＜[PLHD67_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜/hiddenthink＞＜[PLHD68_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜/reflection_never_used_51bce0c785ca2f68081bfa7d91973934＞＜[PLHD75_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜[PLHD91_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜[PLHD80_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜[PLHD67_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜[SOGP_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜[SPEAK_never_used_51bce0c785ca2f68081bfa7d91973934]＞＜[eotu_never_used_51bce0c785ca2f68081bfa7d91973934]＞$

3.$\frac{7}{15}$ $\frac{1}{7}$ $\frac{1}{5}$ $\frac{2}{25}$