Question Number 121807 by abdelsalamalmukasabe last updated on 11/Nov/20
Answered by sukumara3@gmail.com last updated on 14/Nov/20
$${while}\:{cancelling}\:{step},{it}\:{is}\:{not}\:\mathrm{2}{yy}^{'} {x}.{But}\:{it}\:{is}\:\mathrm{2}{y}^{'} {y}^{'} {x}\:{only}. \\ $$