Помогите решить(под буквой а)

[latex] \frac{1}{4}*4 \frac{3}{4}* \frac{16}{57}+(4 \frac{3}{4}+1 \frac{2}{3})* \frac{16}{21}+ \frac{2}{27}*4 \frac{1}{2}=5 \frac{1}{3} [/latex] 1) [latex] \frac{1}{4}*4 \frac{3}{4}* \frac{16}{57}= \frac{1*19*16}{4*4*57}= \frac{1}{3} [/latex] 2) [latex]4 \frac{3}{4}+1 \frac{2}{3}=4 \frac{9}{12}+1 \frac{8}{12}=5 \frac{17}{12}=6 \frac{5}{12} [/latex] 3) [latex]6 \frac{5}{12}* \frac{16}{21}= \frac{77*16}{12*21}= \frac{44}{9}=4 \frac{8}{9} [/latex] 4) [latex] \frac{2}{27}*4 \frac{1}{2}= \frac{2*9}{27*2}= \frac{1}{3} [/latex] 5) [latex] \frac{1}{3}+4 \frac{8}{9}+ \frac{1}{3}= \frac{3}{9}+4 \frac{8}{9}+ \frac{3}{9}=4 \frac{12}{9} =5 \frac{3}{9}= 5\frac{1}{3} [/latex]