Помогите пожалуйста!!

Б) $6 \frac{1}{4} * 1 \frac{2}{5} *8-= \frac{25*7*8}{4*5} = 5*7*2=70 \\ 2)3 \frac{3}{8} * \frac{1}{2} : \frac{9}{16} = \frac{27}{8} * \frac{1}{2} * \frac{16}{9} = \frac{27*16}{8*2*9} =3 \\ 3) \frac{3}{4} *1 \frac{1}{4} * 7 \frac{1}{2} * 2 \frac{1}{4} : 7 \frac{1}{2} = \frac{3}{4} * \frac{5}{4} * \frac{9}{4} = \frac{3*5*9}{4*4*4} = \frac{135}{64} = 2 \frac{7}{64} \\ 4) \frac{15}{16} : 1 \frac{1}{48} : 2 \frac{1}{7} : 2 \frac{2}{49} : \frac{24}{125} = \frac{15}{16} * \frac{48}{49} * \frac{7}{15}$ $* \frac{49}{100} * \frac{125}{24} = \frac{15*48*7*49*125}{16*49*15*100*24} = \frac{3*7*5}{24*4} = \frac{105}{96} = 1 \frac{9}{96}$