निम्नलिखित का योग ज्ञात कीजिए :
(i) ` ab-bc, -ca,ca-ab`
(ii) ` a-b+ab,b-c+bc,c-a+ac`
(iii) `2p^2q^2-3pq+4,5+7pq-3p^2q^2`
(iv) ` l^2+m^2,m^2+n^2,n^2+l^2, 2lm+2mn+2nl`.

Answer

(i)-bc
(ii) `ab+bc+ac`
(iii) `-p62q^2+4pq+9`
(iv) `2(l^2+m^2+n^2+lm+mn+nl)`.