А) 5x>-45
x>-9
___/____>
-9
x∈(-9:+беск)
в) <span>1,2(х + 5) + 1,8х > 7 + 2х
</span>1,2x+6+1,8x>7+2x
1,2x+1,8x-2x>-6+7
x>1
_____/______>
1
x∈(1;+беск)
{ x=6+y
{ y*(6+y)=16
6*y+y^2=16
y^2+6*y-16=0
y1= -11/2 y2= -1/2
x1=6-11/2 = 1/2
x2 = 6-1/2 = 11/2
<span>-2(х-1)х-(х+7)(х^2-7х+49)=-2x-1*x-(x+7)(x-7)^2=-2x-1x-(x+7)^3</span>
Х-4=6 х-4=-6
х=6+4 х=-6-4
х=10 х=-10
3,5*(2 ¹/₇ - 1¹/₅) =
=3,5*(¹⁵/₇ - ⁶/₅)=
=<u>35 </u>* (<u>15*5-6*7</u>) =
10 35
=<u>33 </u>= 3,3
10