Bài 1:Thực hiện phép tính
\(a,\frac{\left(2^3.5.7\right)\left(5^2.7^3\right)}{(2.5.7^2)^2}\)
\(b,\frac{4}{77}+\frac{4}{165}+\frac{4}{285}:\frac{5}{84}+\frac{3}{180}+\frac{4}{285}\)
Bài 2:Tìm x,y
\(a,\left(x+\frac{2}{3}\right).\frac{-3}{5}+\frac{4}{7}=1\frac{4}{7}.x\)
\(b,|5x-2|\le0\)
\(c,(x-7).(x+3)< 0\)
\(d,(x-3).(2y+1)=7\)\((với\)\(x,y\)nguyên)