5:[["$","div",null,{"className":"crumbs","children":[["$","span",null,{"children":["$","a",null,{"href":"/","children":"Главная"}]}],["$","span",null,{"children":["$","a",null,{"href":"/gdz","children":"ГДЗ"}]}],["$","span",null,{"children":["$","a",null,{"href":"/gdz/algebra/9-klass/makarychev","children":["Алгебра"," ",9," класс ","Макарычев"]}]}],["$","span",null,{"children":["Номер ","664"]}]]}],["$","h1",null,{"children":["Номер 664"," — ГДЗ ","алгебра"," ",9," класс ","Макарычев"]}],[["$","section","16759",{"children":[false,["$","div",null,{"className":"sheet-card statement","children":[["$","p",null,{"children":["$","b",null,{"children":["№ 664","."]}]}],["$","div",null,{"dangerouslySetInnerHTML":{"__html":"

Найдите пятидесятый член арифметической прогрессии, если:

\nа) S₂₀ = 1000, S₄₀ = 10 000;
\nб) S₅ = 0,5, S₁₅ = –81.\n

"}}]]}],["$","div",null,{"className":"notice","children":["Разбор этого задания готовится. Пока можно ",["$","a",null,{"href":"/reshit","children":"решить его по фото"}]," — ИИ объяснит по шагам."]}]]}]],["$","p",null,{"children":[["$","a",null,{"href":"/gdz/algebra/9-klass/makarychev/nomer-663","children":["← ","Номер 663"]}]," · ",["$","a",null,{"href":"/gdz/algebra/9-klass/makarychev/nomer-665","children":["Номер 665"," →"]}]," · ",["$","a",null,{"href":"/gdz/algebra/9-klass/makarychev","children":"Все номера"}]]}],["$","script",null,{"type":"application/ld+json","dangerouslySetInnerHTML":{"__html":"[{\"@context\":\"https://schema.org\",\"@type\":\"Question\",\"name\":\"Алгебра 9 класс Макарычев, номер 664\",\"text\":\"Найдите пятидесятый член арифметической прогрессии, если: а) S20 = 1000, S40 = 10 000; б) S5 = 0,5, S15 = –81.\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Ответ: а) a₅₀ = 650; б) a₅₀ = -51,6\"}},{\"@context\":\"https://schema.org\",\"@type\":\"BreadcrumbList\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Главная\",\"item\":\"https://reshay.ai/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"ГДЗ\",\"item\":\"https://reshay.ai/gdz\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Алгебра 9 класс Макарычев\",\"item\":\"https://reshay.ai/gdz/algebra/9-klass/makarychev\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"Номер 664\"}]}]"}}]]

Номер 664 — ГДЗ алгебра 9 класс Макарычев