学年

質問の種類

英語 中学生

リーディングの問題です。 色付き下線部の英文の訳し方がよくわかりません。 どのようにして,回答のようになるのか教えて下さい🙇‍♀️

3 Jill, Ellen, Bob, and Edward lived near a lake/They could go for a swim every day. A man named Mr. Black lived near the lake, too./Sometimes Mr. Black went swimming with the children. One day they asked him to go for a swim with them./Mr. Black said "We can't go for a swim. We may never swim in the lake again." "Why not?" asked Edward. "Because the lake is polluted," said Mr. Black. "There's a new sign at the lake. It says No Swimming, Polluted." "What is polluting the lake?" asked Jill. "Let's go down to the lake and look at it," said Mr. Black. (ア) Mr. Black and the children went to the lake on a sunny Sunday. They looked into the water. It wasn't clean/They walked around the lake and they saw why it wasn't clean. “Look at that *garbage in the water," said Jill. "That's what's polluting the lake.” Edward saw oil floating on the water./"That oil pollutes the water, too,” said Edward. "It comes from boats on the lake." "Come here," said Ellen. "Take a look at this. There are tires in the lake !" "Why would people throw tires into a lake ?" asked Bob. "They just don't stop to think," said Mr. Black. "But they are not the only ones who pollute the lake. The people who run that factory pollute the water, too." Bob looked at Mr. Black/"What can we do? How can we stop the pollution ? he asked. "Well, we must get help from other people. We can't do it alone," said Mr. Black. Mr. Black had a friend who worked for a newspaper company. He asked him to help. The next day the story about the pollution was reported in the newspaper. Many people read about the story. They talked of the pollution. They talked of ways to clean it up. people met at the lake./They came to clean it up./ They cleaned out the garbage. Then they cleaned out the tires./They set up big cans. Then they put signs on the cans. The signs read, "Put Your Garbage Here." /People who lived near the lake came to help./People who had boats came to help./And, people from the factory also One day (イ) came to help. They knew that it would take a long time to get the lake clean again. But they did not give up. They all hoped that someday the "No Swimming” sign would come down and the people could swim in the lake again. 注) 〒garbage=ごみ

解決済み 回答数: 2
数学 高校生

(2)の問題ですが、指針に二次方程式とは書かれてないから…と書かれていますが、どうしてxの2乗の係数が0か0でないかでわけるのでしょうか?💦

168 解答 重要 例題 99 文字係数の方程式 α は定数とする。 次の方程式を解け。 (a²-2a)x=a-2 指針 (1) Ax=B の形であるが, A の部分は文字を含んでいるから, 次のことに注意。 (1) 与式から a(a−2)x=a-2 ① [1] a(a−2)≠0 すなわち a≠0 かつa=2のとき したがって よって 4=0のときは,両辺を4で割ることができない (「0で割る」 ということは考えない。) (2) 2ax²-(6a²-1)x-3a=0 ■定数とする 1 ゆえに a [2] a=0のとき (*), ① から ( 0x=-2 これを満たすxの値はない。 [3] α=2のとき, ① から これはxがどんな値でも成り立つ。 したがって A 0, A=0 の場合に分けて解く。 (2) 問題文に「2次方程式」 とは書かれていないから, x2の係数が0のときと0でない ときに分けて解く。 a-2 x= a(a-2) CHART 文字係数の方程式 文字で割るときは要注意 0で割るのはダメ! x= (2) [1] 2a = 0 すなわち α = 0 のとき, 方程式は すなわち、解は x=0 [2] a=0のとき, 方程式から 0.x=0 a≠0 かつαキ2のとき x=1 a=0のとき 解はない a=2のとき 解はすべての数 1 x=3a, 2a a=0のとき x=0 (x-3a) (2ax+1)=0 A TRAJ JA a=0のときx=3a, \2 18/ 2a x=0 0000 PENDAYE 重要 38, 基本 95 (*) (xの係数)=0のとき は,最初の方程式に戻って 考える。 → 割 STOP= 検討 Ax=B の解 A0 のとき x= A=0のとき (S) 2a B≠ 0 なら 0.x=B 解はない (不能) ・・・ B=0 なら 0.x=0 解はすべての数 (不定) 2a ◄ 1 -3a->> X (x2の係数)=0 のときは, 最初の方程式に戻って考 える。 1 -3a B A -6a² 1 - (6a²-1) @+d²[S] ³.TH) ©> #3 (2 a=0のとき3aキ-1 2a 基本 (1) 次 今 (2) x めよ 指針 解答

解決済み 回答数: 1