Bạn tham khảo!
$a)$ $6$ $.$ $54$ $=$ $27$ $.$ $12$
$→$ $\dfrac{6}{27}$ $=$ $\dfrac{12}{54}$
$→$ $\dfrac{27}{6}$ $=$ $\dfrac{54}{12}$
$→$ $\dfrac{12}{6}$ $=$ $\dfrac{54}{27}$
$→$ $\dfrac{6}{12}$ $=$ $\dfrac{27}{54}$
$b)$ $12$ $.$ $26$ $=$ $3$ $.$ $104$
$→$ $\dfrac{12}{3}$ $=$ $\dfrac{104}{26}$
$→$ $\dfrac{3}{12}$ $=$ $\dfrac{26}{104}$
$→$ $\dfrac{104}{12}$ $=$ $\dfrac{26}{3}$
$→$ $\dfrac{12}{104}$ $=$ $\dfrac{3}{16}$
$c)$ $0,8$ $.$ $0,12$ $=$ $0,3$ $.$ $0,32$
$→$ $\dfrac{0,8}{0,3}$ $=$ $\dfrac{0,32}{0,12}$
$→$ $\dfrac{0,3}{0,8}$ $=$ $\dfrac{0,12}{0,32}$
$→$ $\dfrac{0,32}{0,8}$ $=$ $\dfrac{0,12}{0,3}$
$→$ $\dfrac{0,8}{0,32}$ $=$ $\dfrac{0,3}{0,12}$
$d)$ $-18$ $.$ $1,24$ $=$ $-12$ $.$ $1,86$
$→$ $\dfrac{-18}{-12}$ $=$ $\dfrac{1,24}{1,86}$
$→$ $\dfrac{-12}{-18}$ $=$ $\dfrac{86}{1,24}$
$→$ $\dfrac{1,24}{-18}$ $=$ $\dfrac{86}{-12}$
$→$ $\dfrac{-18}{1,24}$ $=$ $\dfrac{-12}{86}$
$FbBinhne2k88$

a,6/12=27/54

12/6=54/27

6/27=12/54

27/6=54/12

b,12/104=3/26

12/3=104/26

104/12=26/3

3/12=26/104

Sorry bn mik phải ik hok nên chỉ lm đc 2 câu thoii