Question

rezolvați sistemul de ecuație
$x + y = 9 \\ {x}^{2} - {y}^{2} = 16$
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Answer 1

$\left \{ {{x=9-y} \atop {x^{2}-y^{2}=16 }} \right. =\left \{ {{x=9-y} \atop {(9-y)^{2}-y^{2}=16 }} \right. =\left \{ {{x=9-y} \atop {y=\frac{65}{18} }} \right. =\left \{ {{x=9-\frac{65}{18} } \atop {y=\frac{65}{18}}} \right. =\left \{ {{x=\frac{97}{18} } \atop {y=\frac{65}{18}}} \right.$