Hello : <span>x²+y²=25 ...(1) y²-x²=7...(2) (1)+(2) : 2y² = 32 y² = 16 y² = 4² y =4 or y = -4 if : y= 4 subsct in (1) : x² +16 =25 x² =9 x =3 or x = -3 if : y = - 4 same solutions : </span>x =3 or x = -3 the systeme are 4 solutions : (3,4), (-3, 4),(3,-4) , (-3,-4)...( <span>(x,y) format)</span>