Question 842826
This problem looks for the intersection of two circles. 
However they are both centered at (0,0).
{{{x^2+y^2=4}}} has a radius of {{{2}}}.
{{{x^2+y^2=28/5}}} has a radius of {{{sqrt(28/5)}}}.
These two circles are concentric and have no points of intersection.
{{{drawing(300,300,-3,3,-3,3,grid(1),green(circle(0,0,2)),blue(circle(0,0,sqrt(28/5))))}}}