Даны векторы а (3: 1), 6 (2; -4), c(-1; 1), Найти: a) ab; 6) b (a + c). 2. Точки А (1: 5), В (4; 1), С (7; -3) с вершинами треугольника. Найти косинусы углов этого треугольника. 3. Даны векторы а (1; -1) и б (-2, 1). Найти такое число m, чтобы вектор а + mb был перпендикулярен к вектору а.
Agriculture and manufacturing important in all industries.
a)is b) are c) have d) be
2)Consumers .. for some services.
a)does not pay b) does not pays c) do not pay d) not pay
3) What is right for 3 298?
- two thousands two hundred and ninety eight
-two thousand two hundred and ninety eight
4)It is .. to develop agriculture.
a)essential b) nice c) impossible
5) Producers study the market situation (чтобы знать) how many goods to produce. a)to know b) that to know c) to knowing
6)We … … economics last year.
a) didn’t studied b) weren’t studied c) didn’t study d) not studied
7)New workers ……… by the company every year.
a)are employed b) are employing c) employed d) do employ
8)What is right for 2004?
-twenty and four
-twenty oh four
-two thousand and four
9) Living conditions in this country are .. than in my country.
a)badder b) more bad c) worst d) worse
10) The supply of fuel is the .. problem for many European countries.
a)most serious b) more serious c) least serious d) serious
11) I have lived in this country ... 5 years.
a) for b) since c) more d) -
12)They dont have competitors on this market.
a)some b) ever c) any d) a
13) I havent seen him .. he graduated from university.
a)from time b) since c) yet d) for
14)Put the words into the right order: productivity increased recently company has The its.
15)Where . . . his articles last year?
a)did the scientist publish b) does the scientist publish c) has the scientist published
Окей, формула срредней линии трапеции - a+b/2 где а и b- основания трапеции
Пусть меньшее из оснований будет = х
Тогда 2 основание - х+6
Подставим известные значения в формулу:
19 = х+х+6/2
2х+6/2 = 19 (приведем к общему знаменателю)
2х+6/2 = 38/2 (перенесем все значения в правую часть)
2х+6 - 38/2 = 0 (сложим числители)
2-32 /2 = 0 (вынесем общий множитель 2 за скобки)
2(х - 16)/2 = 0 (сокращаем на 2)
х -16 = 0 (перенесем -16 в правую часть)
х = 16
16 это 1 основание (меньшее)
Найдем 2 основание
16+6 = 22
ответ: 22, 16
Объяснение: