(A) Dots, ka \(a+b=c\). Pierādīt, ka \(2a^{2} \geqq c^{2}-2b^{2}\).
(B) Dots, ka \(a+b+c=d\). Pierādīt, ka \(3a^{2} \geq d^{2}-3b^{2}-3c^{2}\).