<span>{2х-1>0 {2x>1 {x>0.5
{15-3х>0 {-3x>-15 {x<5
Ответ: (0,5;5)</span>
0,5*4+x=-1
x=-3
(x,y)=(-3,4)
a) (2,5х+3)(4х-1)-2,5х(4х+2)<3
10x^2-2,5х+12х-3-10x^2-5х<3
4.5x<9
x<2
б)(1-4х)^2-(8х-1)(2х+1)>0
1-8х+16х^2-16x^2-8x+2x+1>0
-14x>-2
x<1/7
Использованы свойства степени
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3(а-2) -(а+4) = 3а - 6 - а - 4 = 2а - 10
При а = -1,5 2а - 10 = 2*(-1,5) - 10 = -3 - 10 = -13
Ответ. -13