Question

Решите уравнения
$25 - 6y^{2} = 57$
$57 - x2y^{2} = 25$
$10 - y^{2} = 3$

Answer 1

1)6y²=25-57
6y²=-32
y²=-16/3
нет решения
2)х²у²=57-25
х²у²=32ху=+-4√2
3)у²=10-3
у²=7
у=+-√7

Answer 2

$25-6y^2=57 \iff -6y^2=57-25 \iff 6y^2=-32\ \textless \ 0 \\ NET \\ 10-y^2=3 \iff 7-y^2=0 \iff ( \sqrt{7}-y)( \sqrt{7}+y)=0 \\ \sqrt{7}-y=0 \iff y= \sqrt{7} \\ \sqrt{7}+y=0 \iff y=- \sqrt{7}$