Question

a+b-c=7and ab-bc-ca find a^2+b^2-c^2 pls answer step by step​

Answer 1

please correct your question here is ab-bc-ca = 20

(a+b+c)^2= a2+b2+c2+2(ab+bc+ca)

7^2 = a2+b2+c2+ 2×20

a2+b2+c2 = 49 - 40

a2+b2+c2 = 9