1) 9х -11>5(2х-3)
9x-11>10x-15
9x-10x>-15+11
-1x>-4 *(-1)
x<4
(-бесконечност;4)
2) х^2 + 7х -8 ≥ 0
D = b2 - 4ac
D = 49 + 32 = 81 = 9^2
x1,2 = -b ± √D/2a
x1 = -7 + 9/2 = 2/2 = 1
x2 = -7 - 9/2 = - 16/2 = -8
ответ: x1 = 1; x2 = -8(не удол)
1^2+7+1-8>=0
8-7>=0
1>=0
[1;бесконечност+)
