1) 2т 49кг= кг 15ц 6кг= кг 74.000г= кг 8т 3ц 16кг= кг 2) а) 4т 68кг + 9ц 52кг= т кг б) 3ц -25кг 925г= ц кг г 3) коробка с 60 конфетами весит 2кг,а без конфет-200г.какова масса одной конфеты,если все они одинаковые.
Anna: Hello, is that you, Mary? How are you? Why yesterday did not go to class? Mary: Hi Anna. I felt bad. And couldn't even get up. A: What happened to you? M: I don't know. I haven't went to the doctor. I had a high temperature. A: can you go to institute today? M: I'm Afraid not. This morning I visit the doctor. I feel that I have a few days to stay in bed. Really sorry we have to miss lectures. A: Nothing to worry about. Don't have to come if you don't feel. Of course, you need to stay in bed. If you want to borrow my notes. Can I visit you today? M: Of Course. Come immediately after lessons. A: I'm Sorry, but after school I have to go to the library to get some books for discussion. M: don't go to the library. I have many interesting books. You can take any of them. A: Well. I can come to you on the 41 tram? M: Yes. But don't come on the tram. Near my house opened a new metro station and takes me all of fifteen minutes to reach the Institute by metro. A: Very well, but I have to go to College. Yet. M: see you Then. Don't forget to bring me your notes. Give me a call if you can't come.
R=√13; АВ=√39; AC=x; BC=3x; AC - ?; BC - ?; Радиус описанной вокруг треугольника окружности находится по формуле: R=AB/2SinC; SinC=AB/2R; SinC=√39/2√13; Найдем CosC по основному тригонометрическому тождеству: (SinC)^2 + (CosC)^2=1; (CosC)^2=1-(√39/2√13)^2; (CosC)^2=1 - 39/52=13/52=0,25; CosC=-√0,25=-0,5 (берём c минусом, так как угол С тупой); По теореме косинусов: (√39)^2=(3х)^2+х^2-2*3х*х*(-0,5); 39=9х^2+х^2+3х^2; х^2=3; х=√3 (отрицательный корень не нужен); сторона АС равна √3; сторона ВС равна 3х=3√3; ответ: √3; 3√3
