Question

Aratati ca numarul a=radical din 288 la puterea 2 - 285 ori 288 - 135 este numarul rational

Answer 1

$\sqrt{288^{2}-285\cdot288-135} =\\ \\ \sqrt{288^{2}-82080-135} =\\ \\\sqrt{288^{2}-82215} =\\ \\ \sqrt{82944-82215} =\\ \\ \sqrt{729}= \\ \\ \sqrt{27^{2}} =\ \\\\=27$