(2x-1)(3x+5)< 0 (4x+3)(5x+2)> 0

1) х1 = 6/12 = 1/2
х2 = -20/12 = - 5/3

2) х1 = (-23+7)/40 = - 2/5
х2 = (-23-7)/ = - 3/4

1) 6х^2 + 10х - 3х - 5 < 0
6х^2 + 7х - 5 < 0
D = 49 + 120 = 169
х1 = (-7+ 13)/12 = 1/2
х2 = (-7-13)/12 = - 5/3
 1/2 > x > - 5/3

2) 20х^2 + 8х + 15х + 6 > 0
20х^2 + 23х + 6 > 0
D = 529 - 480 = 49
х1 = (-23+7)/40 = - 2/5
х2 = (-23-7)/ = - 3/4
-3/4 > х > -2/5