1) {x^2 +y^2 =13
{x^2 - y^2 =5; 2x^2=18; x^2=9; x=-3 ili x=3
{x^2+y^2=13 ili {x^2+y^2=13
{x=-3 {x=3
y^2=13-9 y^2=13-9
y^2=4
y=-2 ili y=2
(-3;-2); (-3;2) : (3;-2); (3;2) Все в ответ!
2 ) {x>-3
{x<3/2; ------------------- -3------------------1,5--------------->x
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x⊂(-3;1,5)