Question

plz do 1 and 2 question of question 3 will say thanks and brainliest

Answer 1

Answer:

$(11 + \sqrt{11} )(11 - \sqrt{11} ) \\ {11}^{2} - { (\sqrt{11}) }^{2} \\ 121 - 11 \\ = 110 \\ \\ \\ \\ (5 + \sqrt{7} )(5 - \sqrt{7} ) \\ = {5}^{2} - {( \sqrt{7}) }^{2} = 25 - 7 = 18$