Question 1061575
Subtract eq. 2 from eq. 1,
{{{x^2+y^2-x^2+2y^2=17-(-31)}}}
{{{3y^2=48}}}
{{{y^2=16}}}
{{{y=4}}} and {{{y=-4}}}
So then,
{{{x^2+16=17}}}
{{{x^2=1}}}
{{{x=1}}} and {{{x=-1}}}
(-1,4)
(-1,-4)
(1,4)
(1,-4)