1)1/5 + 4/15=3+4/15=7/15
2)2/3 - 5/12=8-5/12=3/12=1/4
3)5 1/7 + 7 13/21=5/7+13/3=106/21=5 1/21
4)8/15 - 2 23/30=8/15-23/15=-1.
Желаю удачи и до встречи.
X(x+6)<18
1/27(x+3)^2<1
3(-1-3^1/2)<x<3((3^1/2)-1)
(3(-1-3^1/2), 3((3^1/2)-1))
(2х-1)*(3х+4)-6х^2=1
6х^2+5х-4-6х^2=1
5х=5
х=1
6/ (x + 1) + 10/(x^2 - 1) + 1 - 5/(x - 1) = 0
D = R \ { - 1; 1}
6 (x - 1) + 10 + (x^2 - 1) - 5(x + 1) = 0
6x - 6 + 10 + x^2 - 1 - 5x - 5 = 0
x^2 + x - 2 = 0
D = 1 + 8 = 9
x1 = ( - 1 + 3)/2 = 2/2 = 1
x2 = ( - 1 - 3)/2 = - 4/2 = - 2
Ответ
- 2