a)-5/6 .12/7 . ( -21/15) b)1/6 . 9/-9 . ( -12/11) c) (17/18 : 51/36) . 3/5 d) (1/7)^2 . 7^2 e) (0,125)^3 . 512 f) (0,25)^4 . 1024

Giải thích các bước giải:

a)$\frac{-5}{6}$ .$\frac{12}{7}$ .$\frac{-21}{15}$ 

= $\frac{-5.12.(-21)}{6.7.15}$ 

=$\frac{1260}{630}$ =2

b) $\frac{1}{6}$ .$\frac{9}{-9}$ .$\frac{-12}{11}$

=$\frac{1}{6}$ .(-1) .$\frac{-12}{11}$ 

$\frac{1.(-1).(-12)}{6.11}$

=$\frac{12}{66}$ =$\frac{2}{11}$

c) ($\frac{17}{18}$ : $\frac{51}{36}$ ).$\frac{3}{5}$

=$\frac{2}{3}$ .$\frac{3}{5}$

=$\frac{2}{5}$ 

d) ($\frac{1}{7}$ )$^{2}$ .7$^{2}$

=$\frac{1}{49}$ .49=1

e) (0.125)$^{3}$ .512

=($\frac{1}{8}$ )$^{3}$ .512

=$\frac{1}{512}$ .512=1

f) (0.25)$^{4}$ .1024

=1/256.1024=4