Question

if (a+b+c)(b-c)=ab -c² show that​

Answer 1

(a+b+c)(b-c)=ab-c^2

=>ab-ac+b^2-bc+bc-c^2=ab-c^2

=>ab-ab-ac+b^2-bc+bc-c^2+c^2=0

=>b^2-ac=0

=>b^2=ac