Амалдарды орындаңдар. 1) 2 1/2·(2/15−3 5/6)+1/4; 2) −1 1/7·(4/5+19/20)·(6 5/6+4 2/3); 3) (6 3/8−2 3/4)·(−4)+7/18·9; 4) 9 1/6:(4 1/3−8)+24:3/8

1) \(2\frac12=\frac52\), \(3\frac56=\frac{23}{6}\).

\(\frac52\left(\frac2{15}-\frac{23}{6}\right)+\frac14=\frac52\left(-\frac{111}{30}\right)+\frac14=-\frac{37}{4}+\frac14=-9\).

2) \(-1\frac17=-\frac87\), \(\frac45+\frac{19}{20}=\frac{7}{4}\), \(6\frac56+4\frac23=\frac{41}{6}+\frac{14}{3}=\frac{23}{2}\).

\(-\frac87\cdot\frac74\cdot\frac{23}{2}=-23\).

3) \(6\frac38-2\frac34=\frac{51}{8}-\frac{22}{8}=\frac{29}{8}\).

\(\frac{29}{8}\cdot(-4)+\frac7{18}\cdot9=-\frac{29}{2}+\frac72=-11\).

4) \(4\frac13-8=\frac{13}{3}-8=-\frac{11}{3}\).

\(9\frac16:\left(-\frac{11}{3}\right)+24:\frac38=\frac{55}{6}\cdot\left(-\frac3{11}\right)+64=-\frac52+64=\frac{123}{2}=61\frac12\).

Жауап: 1) \(-9\); 2) \(-23\); 3) \(-11\); 4) \(61\frac12\).