No-584(2;4;6) помогите пожалуйста срочно надо. плиз

$2)( \frac{7-4}{12} )* \frac{16}{19}= \frac{3}{12}* \frac{16}{19} = \frac{3*4}{3*19}= \frac{4}{19} ; 4)( \frac{11+4}{24})* \frac{8}{5}= \frac{15}{24}* \frac{8}{5}= \frac{3*1}{3*1}=1;$ ; $6) (6 \frac{16}{16}-2 \frac{5}{16})* \frac{4}{25}=4 \frac{11}{16}* \frac{4}{25}= \frac{75}{16}* \frac{4}{25}= \frac{3*1}{4*1}= \frac{3}{4}$