a)

ОДЗ:x²-9>0(x-3)(x+3)>0x=3 x=-3 + - +------- -3 ----------- 3 -----------\\\\\\\\\ \\\\\\\\\\\\x∈(-∞; -3)U(3; +∞)D(y)=(-∞; -3)U(3; +∞)б)

ОДЗ:1) x²+9x-10≥0 x²+9x-10=0 D=9² -4*(-10)=81+40=121=11² x₁=(-9-11)/2=-10 x₂=(-9+11)/2=1 (x+10)(x-1)≥0 + - +---------- -10 ---------- 1 -----------\\\\\\\\\\\\ \\\\\\\\\\\\\\x∈(-∞; -10]U[1; +∞)2) x-8≠0 x≠8В итоге ОДЗ: x∈(-∞; -10]U[1; 8)U(8; +∞)D(y)=(-∞; -10]U[1; 8)U(8; +∞)в)

ОДЗ:1) 5x+2≥0 5x≥ -2 x≥ -0.42) x≠0В итоге ОДЗ: x∈[-0.4; 0)U(0; +∞)D(y)=[-0.4; 0)U(0; +∞)a)

ОДЗ: x²-10x+21≥0x²-10x+21=0D=(-10)²-4*21=100-84=16=4²x₁=(10-4)/2=3x₂=(10+4)/2=7 + - +-------- 3 ---------- 7 ------------\\\\\\\\\\ \\\\\\\\\\\\\x∈(-∞; 3)U(7; +∞)D(y)=(-∞; 3)U(7; +∞)б)
(x+7)} }{x-6} )
ОДЗ:1) (x-3)(x+7)≥0 x=3 x= -7 + - +-------- -7 --------- 3 ----------\\\\\\\\\\ \\\\\\\\\\\\\\x∈(-∞; -7]U[3; +∞)2) x-6≠0 x≠6В итоге х∈(-∞; -7]U[3; 6)U(6; +∞)D(y)=(-∞; -7]U[3; 6)U(6; +∞)в)

ОДЗ:1) x+5≥0 x≥ -52) 4x-2≠0 4x≠2 x≠0.5В итоге ОДЗ: х∈[-5; 0.5)U(0.5; +∞)D(y)=[-5; 0.5)U(0.5; +∞)