Question

If x=9-4root5then find the value of x suare

Answer 1

Answer:..

$x = 9 - 4 \sqrt{5 } \\ {x }^{2} = {(9 - 4 \sqrt{5} )}^{2} \\ {x}^{2} = {9}^{2} - 2(9)(4 \sqrt{5} ) + {(4 \sqrt{5} )}^{2} \\ {x}^{2} = 81 - 72 \sqrt{5} + 80 \\ {x}^{2} = 81 - 160 + 80 \\ {x}^{2} = 0 \\ \\ \\ hopes \: it \: helps \\ thank \: and \: mark \: as \: brainliest$

Answer 2

Answer:

(9-4 root 5 ) root 2 = 161 -72 root 5

Step-by-step explanation:

(9- 4 root 5)^ 2

=(9)^2 +4 root 5- 2×9×4root 5

=81 +80- 72 root5

=161 - 72 root 5