Question

Помогите решить пожайлуста!!!

Answer 1

$\left \{ {{x+y=50} \atop {50x+100y=3500}} \right. \; \left \{ {{x=50-y} \atop {x+2y=70}} \right. \; \left \{ {{x=50-y} \atop {(50-y)+2y=70}} \right. \; \left \{ {{x=50-y} \atop {y=20}} \right. \; \left \{ {{x=30} \atop {y=20}} \right.$

Детей 30, взрослых 20.

Answer 2

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