Question

1£®ÓÃÄãϲ»¶µÄ·½·¨×ö£®
$\frac{4}{5}$¡Á$\frac{5}{6}$+$\frac{2}{5}$¡Â$\frac{3}{5}$    
 $\frac{3}{8}$¡Á$\frac{7}{12}$+$\frac{5}{8}$¡Â$\frac{12}{7}$
$\frac{4}{5}$¡Á$\frac{4}{7}$¡Á$\frac{5}{4}$-$\frac{1}{2}$           
 $\frac{1}{8}$¡Á58+$\frac{1}{8}$¡Á41+$\frac{1}{8}$£®

Answer 1

·ÖÎö £¨1£©ÏÈËã³Ë·¨ºÍ³ý·¨£¬ÔÙËã¼Ó·¨£»
£¨2£©¡¢£¨4£©¸ù¾Ý³Ë·¨·ÖÅäÂɽøÐмòË㣻
£¨3£©¸ù¾Ý³Ë·¨½»»»ÂɽøÐмòË㣮

½â´ð ½â£º£¨1£©$\frac{4}{5}$¡Á$\frac{5}{6}$+$\frac{2}{5}$¡Â$\frac{3}{5}$
=$\frac{2}{3}$+$\frac{2}{3}$
=$\frac{4}{3}$£»

£¨2£©$\frac{3}{8}$¡Á$\frac{7}{12}$+$\frac{5}{8}$¡Â$\frac{12}{7}$
=$\frac{3}{8}$¡Á$\frac{7}{12}$+$\frac{5}{8}$¡Á$\frac{7}{12}$
=£¨$\frac{3}{8}$+$\frac{5}{8}$£©¡Á$\frac{7}{12}$
=1¡Á$\frac{7}{12}$
=$\frac{7}{12}$£»

£¨3£©$\frac{4}{5}$¡Á$\frac{4}{7}$¡Á$\frac{5}{4}$-$\frac{1}{2}$
=$\frac{4}{5}$¡Á$\frac{5}{4}$¡Á$\frac{4}{7}$-$\frac{1}{2}$
=1¡Á$\frac{4}{7}$-$\frac{1}{2}$
=$\frac{4}{7}$-$\frac{1}{2}$
=$\frac{1}{14}$£»

£¨4£©$\frac{1}{8}$¡Á58+$\frac{1}{8}$¡Á41+$\frac{1}{8}$
=$\frac{1}{8}$¡Á£¨58+41+1£©
=$\frac{1}{8}$¡Á100
=12.5£®

µãÆÀ ¿¼²éÁËÔËË㶨ÂÉÓë¼ò±ãÔËË㣬ËÄÔò»ìºÏÔËË㣮עÒâÔËËã˳ÐòºÍÔËËã·¨Ôò£¬Áé»îÔËÓÃËùѧµÄÔËË㶨Âɼò±ã¼ÆË㣮