here is how to solve it:
1) isolate x for x+y=2:
x=2-y
2)now plug this value in 3x^2-y^2=1
3(2-y)^2-y^2=1
simplify to get 2y^2-12y+11=0
and you get:[tex]y_1=3+ \sqrt{ \frac{7}{2} } ,y_2=3- \sqrt{ \frac{7}{2} } [/tex]
3)plug these(y1,y2) values in x+y=2
and you get:[tex]x_1=-1- \sqrt{ \frac{7}{2} } ,x_2=-1+ \sqrt{ \frac{7}{2} } [/tex]
hope that i helped
