y=x^2-1
y=-3x-2
y=x^2
x^2+y^2=1
25x^2+9y^2=225
5x^2+2y^2=10
x^2+y^2=36
y=x/5-7
y=-1/2x+4
x^2+9y^2=9
y=-2x^2
y=4x^2+3
4x^2+36y^2=144
x^2+y^2=16
y=5x+1/2
x^2+y^2=81
