Question

Find a polynomial whose zeros are (9+4√5)and(9-4√5)

Answer 1

$x = 9 + 4 \sqrt{5} \: \: and \: x = 9 - 4 \sqrt{5} \\ x - (9 + 4 \sqrt{5} ) = 0 \: \: \: \: x - (9 - 4 \sqrt{5} ) = 0\\ x - 9 - 4 \sqrt{5} = 0 \: \: \: \: x - 9 + 4 \sqrt{5} = 0 \\ {(x - 9)}^{2} - {(4 \sqrt{5)} }^{2} = 0 \\ {x}^{2} - 18x + 81 - 80 = 0 \\ {x}^{2} - 18x + 1 = 0$