Question

Verify that (x-y) -1 # x-1 - y-1 by taking x=-2/7, y=4/7​

Answer 1

$LHS:(x-y)-1$

$=(\frac{-2}{7} -\frac{4}{7} )-1\\\\=(\frac{-6}{7})-1\\ \\=(\frac{-6-7}{7})\\\\=\frac{-13}{7}$

$RHS:x-1-y-1$

$=\frac{-2}{7}-1-\frac{4}{7} -1\\ \\=\frac{-2-7-4-7}{7}\\ \\=\frac{-20}{7}$

$LHS\neq RHS$

Hence , proved .