Question

12/19•(1 7/12 •4 13/21)= (3 2/7•25,8)•7/23=

(6 8/11•4/5)•1 1/4=

2 5/6•(17,8•7/17)=

Answer 1

12/19•(1 7/12 •4 13/21)=

$\frac{17}{12} \times 4 \frac{13}{21} = \frac{17}{12 } \times \frac{97}{21} = \frac{17 \times 97}{12 \times 21} = \frac{1649}{252} = 6 \frac{137}{252}$

$\frac{12}{17} \times 6 \frac{137}{252} = \frac{12}{19} \times \frac{1649}{252} = \frac{12 \times 1649}{19 \times 252} = \frac{19788}{4788} = \frac{1649 \times 12}{399 \times 12} = 4 \frac{53}{399}$