Question

quanto é por favor!!!

Answer 1

Para achar o "x" usei o metodo de adicao!

$a) \left \{ {{x+y=-2} \atop {x-y=-22}} \right.$
2x=-24 ⇒x=-24/2⇒ x=-12


$b) \left \{ {{x+y=-2} \atop {x-y=-22}} \right. → \left \{ {{-12+y=-2} \atop {-12-y=-22}} \right. → \left \{ {{y=12-2} \atop {-y=12-22}} \right. → \left \{ {{y=10} \atop {-y=-10}} \right. → \left \{ {{y=10} \atop {y=10}} \right.$