1)х+2<5х-2х+6
х+2<3х+6
х+2-3х-6 < 0
-2х-4 < 0
-2х < 4
х < -2
2) 4х - 4 - (9х-5) >= 3
4х - 4 - 9х + 5 - 3 >= 0
-5х >= 2
х >= -0,4
3) 2х-2 >= 5х-3х-2
2х-2 = 2х-2
4) 3х>12+11х
5х-1<0
1. 3х-12-11х > 0
-8х > 12
х > -1,5
5х < 1
х < 0,2
=8a^3 - 12a^2 * b +6ab^2 - b^3 -8a^3 - 12a^2 * b - 6ab^2 - b^3 = - 2b^3 - 24a^2 * b= -2b*(b^2+12a)
По теореме Виета x1 + x2 = 4, x1 * x2 = b
2x1 + 3x2 = 5
2(x1 + x2) + x2 = 5
2 * 4 + x2 = 5
x2 = -3
x1 = 4 - x2 = 7
b = x1 * x2 = 7 * (-3) = -21