1. = 7,2/(-0,3) = -24
2. 10/17≈0,59
12/17≈0,70
13/17≈0,76
14/17≈0,82
Ответ: 3) 13/17
3. = √(175/7) = √25 = √5² = 5
Ответ: 1) 5
4. 5х+х= -12
6х = -12
х= -12:6
х= -2
5. А-3)
Б-1)
В-2)
6. q = b₍n+1₎ / b₍n₎ = 2b₍n₎ / b₍n₎ = 2
S₍n₎ = (b₍1₎ * (1-q^n)) / (1-q)
S₍6₎ = (b₍1₎ * (1-q^6)) / (1-q) = (-6*(1-2^6)) / (1-2) = (-6*(-63)) / (-1) = -378
(₍ ₎ - нижний индекс; ^ в степени)
7. = ((а-3)(а+3))/(6а(а-3)) = (а+3)/6а = (-0,3+3)/(6*(-0,3)) = 2,7/(-1,8) = -1,5