$7x^2-21y^2{x}^2=28$

$($Write an equation for the cross section at $z=0$ using $x$ and $y.)$

$($Wrike an equation for the creas section at $y=-2$ using $x$ and $z.)$

$($Write an equation for the cross section at $y=0$ using $x$ and $z.)$

$($Write an equation for the cross section at $y=2$ using $x$ and $2.)$

$($Write an equation for the oross section at $x=0$ using $y$ and $2.)$