Question

Пожалуйста!!! Помогите! ​

Answer 1

$\displaystyle 1)x^2=0,25\\\\ x^2=\frac{1}{4}\\\\ x=б\frac{1}{2}=б0,5\\\\ 2)x^2-15=0\\x^2=15\\x=б\sqrt{15}\\\\ 3)57-2y^2=25\\-2y^2=25-57\\-2y^2=-32\\y^2=16\\y=б4\\\\ 4) 25-6y^2=57\\-6y^2=57-25\\-6y^2=32\\y\notin R$