а) ОДЗ: [tex]x^2+8x-9\neq 0[/tex]

[tex]D=b^2-4ac = 64 - 4*(-9)=64+36=100\\x_{1}=\frac{-b-\sqrt{D} }{2a}=\frac{-8-10}{2}=-9\\x_{2}= \frac{-b+\sqrt{D} }{2a}=\frac{-8+10}{2}=1[/tex]

х∈(-∞; -9)U(-9; 1)U(1; +∞)

б) ОДЗ: 5x + 1 > 0

5x > -1

x > -1/5

х∈(-1/5; +∞)

в) ОДЗ: [tex]\left \{ {{9-3x\geq 0} \atop {2x+5\geq 0}} \right.[/tex]

[tex]\left \{ {{x\leq 3} \atop {x\geq 2,5}} \right.[/tex]

х∈[2,5; 3]

г) ОДЗ:

[tex]\left \{ {{-x+2\geq 0} \atop {6-2x > 0}} \right. \\[/tex]

[tex]\left \{ {{-x+2\geq 0} \atop {6-2x > 0}} \right. \\\left \{ {{x\leq 2} \atop {x\leq 3}} \right.[/tex]

х∈(-∞; 2]

д) ОДЗ: [tex]x\neq 0[/tex]

2x+4>0

2x>-4

x>-2

х∈(-2; 0)U(0; +∞)

е) ОДЗ:

[tex]\left \{ {{4x+2\geq 0} \atop {x+2\neq 0}} \right.[/tex]

[tex]\left \{ {{x\geq -\frac{1}{2} }\\ \atop {x\neq -2}} \right.[/tex]

х∈(1/2; +∞)