Умоляю .
1. выполните действия : 3^(-² ): (--³) +0,3^(-¹)-(-5)^0
2. известно , что порядок числа а равен 21 . найдите порядок числа 0,001*а.
3. докажите , что значение выражения 10^(6n+8)*0,01^(3n+4)

Task 6. Read the sentences and say True or False

1. People do morning exercises, jog in the morning and train themselves in club

Watching TV makes people feel good,

3. People only watch sports games, listen to sports news

4. Boys and girls play hockey and golf at the lessons.

S. Regular exercises will make your heart and lungswock bad

6. Physical training is an important subject at school.

7. If you go in for sports you have cutch cold.

Children must take care of their health

9. Unhealthy people live longer,

А) Просто, надо раскрыть скобки, как в алгебре.
(2a - 3b)(a + 2b) = 2a^2 - 3ab + 4ab - 6b^2 = 2a^2 + ab - 6b^2
б) Длина векторного произведения
|(2a - 3b)x(a + 2b)| = |2a - 3b| * |a + 2b| * sin ((2a-3b); (a+2b))
|a| = 5; |b| = 2; (a; b) = 3pi/4; sin(a;b) = √2/2; cos(a;b) = -√2/2
|2a-3b| = √[(2a)^2+(3b)^2-2a*3b*cos(a;b)] = √(100+36+10*6*√2/2) ~ 13,36
|a+2b| = √[a^2+(2b)^2-a*2b*cos(pi-(a;b))] = √(25+16-5*4*√2/2) ~ 5,18
|(2a - 3b)x(a + 2b)| = |2a - 3b| * |a + 2b| * sin((2a-3b); (a+2b)) =
= 13,36*5,18*√2/2 ~ 48,935