Grade

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Mathematics Senior High

(1)の問題でこれを解いてのところで n=31を出す途中式を教えてください!!

を代て 標 例題 7等差数列の決定(2) 7 和の条件から <<< 基本例題 6 (1)初項が-10, 末項が200, 和が2945 である等差数列の項数nと公差d を求 めよ。 (2)初項から第10項までの和が555 で, 初項から第20項までの和が810 であ ある等差数列の初項αと公差d を求めよ。 CHART GUIDE 等差数列の和の条件が与えられた問題 S₁ = n(a+1) 2 S,= n{2a+(n-1)d} 2 (1)初項α,未項し,和 S”がわかっているから1を利用し,まず”を求める。 (2)Sim S30 がわかっているから,2を利用し,aとdの連立方程式を作る。 解答 77+(n-1)(3) [(2) 類 星薬大] 1 (1) 条件から n(-10+200)=2945 S=(a+1) これを解いて n=31 8-02- また,200-10+(31-1)d から d=7 ←an=a+(n-1)d 10{2a+(10-1)d}=555, 2 001 よって 2a+9d=111 ① ② を解いて a=69, d=-3 (2)初項から第n項までの和をS とすると, S10=555, S20=810 であるから26項 +S+1++ 大と 1+81+SI+a)-001- 2 -20{2a+(20−1)d}=810 S=n(2a+ (n-1)d] AES a18-(000)001 ①, 2a+19d=81 ② ②①から 10d=-30 頂 箱は、正の数を! by Lecture 等差数列の5要素 等差数列に関係する要素として 初項 公差 数 末項 和 の5つの要素があり、この うち3つの要素がわかれば Sp a d n 関係式 ↓ l=a+(n-1)d,S,=1/2n(a+1) を使って残りの2つの要素 がわかる。

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English Senior High

高校英語の問題です。 (21) (26) (24)の答えを教えてください🙇‍♀️

3 正 問題 誤りのある箇所を選び、正しい形を書きなさい。 22は誤りのある箇 所がなければNO ERROR を選びなさい。 121 In lists of the most speaking languages of the world, it has been ② customary to rank them by order of their total numbers of speakers, although there are considerable difficulties in gestimating more than very approximate totals. (学習院大) りのある箇所 正しい形 □□ 22 Nothing seems to irritate William more than having to explain his actions in that unfortunate ③ matter to everyone with who he talks. NO ERROR (早稲田大) 祭りのある箇所 正しい形 4 with whom □□ 23 The bus arrived ② lately on account of rain, so we ③ missed the train we were supposed to take. (桜美林大) D 誤りのある箇所 正しい形 to lately □□24 By means of my excitement about the interview tomorrow and the ② noise ③ from upstairs, I couldn't sleep. 誤りのある箇所 had 正しい形 small ■□ 25 Frankly speak, I find the class boring. (立命館大) (東洋大) 誤りのある箇所 Charlo ③ 正しい形 spoke □□ 26 Another award winner was “Paro," a furry seal* which has sensors beneath gits fur and whiskers. When the seal is stroked, it responds by opening and closing its eyes and move its flippers**. * furry seal : 毛皮におおわれたアザラシ **flipper : ひれ足 誤りのある箇所 正しい形 (中央大)

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Mathematics Junior High

全くわからなくて色々調べなながらやってたら半ページに3時間もかかりました、、 これは遅い方ですか?

Dialogue A: Speaking of school, what's your favorite subject? 学校と言えば、いちばん好きな科目は何ですか。 B: It's English. 英語です。 A: Me, too. 私も同じです。 1 ( 内から適切なほうを選びなさい。 A 1000000 1. (Seeing/Seen) from a distance, the two buildings look alike. 2. (Knowing not/Not knowing) how to get there, I asked the way. 3. (Moving/Moved) by his song, the audience gave him a big hand. 4. My father told a good joke, (making/made) my mother laugh. 5. (Building/Built) of brick, the house looks elegant. 6. (Having/Had) a lot of homework, my brother couldn't watch TV last night. 2 [ ]内の動詞を適切な形にして下線部に入れなさい。 ただし, それぞれ1回しか使えません。 200000 1. 2. 3. 4. Not 5. Never up at five this morning, I feel sleepy now. kind and friendly, Mike is loved by everybody. alone, I felt lonely. [be/feel/get/leave/try] well, I went to bed early last night. the video game before, I didn't know how to do 3 各組の文がほぼ同じ意味になるように,( )に適切な語を入れなさい。 A B 1. (a) I read a book and lay down on the bed. (b) I read a book, ( ) down on the bed. 2. (a) While Sally was walking along the river, she met an old friend. (b)( ) along the river, Sally met an old friend. 3. (a) They spent some time together and fell in love with each other. (b) They spent some time together, ( 4. (a) As Tom had worked overtime, he was really tired. (b) ( )( ) in love with each other. ) overtime, Tom was really tired. 5. (a) Because he had never seen a panda, he was glad to see one in the zoo. (b) ( )( in the zoo. ) ( ) a panda, he was glad to see one

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