C-14-Q014mediumsingle_mcqab=cd\dfrac{a}{b}=\dfrac{c}{d}ba=dc হলে যোজন ও বিয়োজনের ফল—aa+ba−b=c+dc−d\dfrac{a+b}{a-b}=\dfrac{c+d}{c-d}a−ba+b=c−dc+dba+bc+d=a−bc−d\dfrac{a+b}{c+d}=\dfrac{a-b}{c-d}c+da+b=c−da−bca−ba+b=c+dc−d\dfrac{a-b}{a+b}=\dfrac{c+d}{c-d}a+ba−b=c−dc+dda+ba=c−dc\dfrac{a+b}{a}=\dfrac{c-d}{c}aa+b=cc−d