\(\left(7^{1997}-7^{1995}\right):\left(7.7^{1994}\right)\\ =\left(7^{1997}-7^{1995}\right):\left(7^{1+1994}\right)\\ =\left(7^{1997}-7^{1995}\right):7^{1995}\\ =\left(7^{1997}:7^{1995}\right)-\left(7^{1995}:7^{1995}\right)\\ =\left(7^{1997-1995}\right)-1\\ =7^2-1\\ =48\)
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