Question

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Answer 1

3.

$sqrt{265^2 - 96^2} =sqrt{(265 - 96) (265 + 96)} =sqrt{169*361} =13*19=247$

2.

$x^2-17x+42=0\x^2+14x-51  neq 0$

Получается

х=14

1.

$54-14sqrt{5} =(7-sqrt{5} )^2\86+18sqrt{5} =(9+sqrt{5} ^2)[tex]sqrt{54-14sqrt{5}} +sqrt{86+18sqrt{5}} =16$\[/tex]