Bài 35 trang 22 SGK Toán 7 tập 1

\(\eqalign{
& a)\,\,{\left( {{1 \over 2}} \right)^m} = {1 \over {32}} \Rightarrow {\left( {{1 \over 2}} \right)^m} = {1 \over {{2^5}}} \cr
& \Rightarrow {\left( {{1 \over 2}} \right)^m} = {\left( {{1 \over 2}} \right)^5} \Rightarrow m = 5 \cr
& b)\,\,\,{{343} \over {125}} = {\left( {{7 \over 5}} \right)^n} \Rightarrow {{{7^3}} \over {{5^3}}} = {\left( {{7 \over 5}} \right)^n} \cr
& \Rightarrow {\left( {{7 \over 5}} \right)^3} = {\left( {{7 \over 5}} \right)^n} \Rightarrow n = 3 \cr} \)