Question

efectuati (2+√7)²ajutatima va rog frumos..

Answer 1

${(2 + \sqrt{7}) }^{2} = \\ \\ {2}^{2} + 2 \times 2 \sqrt{7} + { \sqrt{7} }^{2} = \\ \\ 4 + 2 \times 2 \sqrt{7} + { \sqrt{7} }^{2} = \\ \\ 4 + 4 \sqrt{7} + 7 = \\ \\ 11 + 4 \sqrt{7}$