ОДЗ:
x² -10x+25 ≥0
5-4x-x²
5-4x-x²≠0
x²+4x-5≠0
D=16+20=36
x₁≠ -4-6 ≠ -5
2
x₂≠ -4+6 ≠ 1
2
5-4x-x²= -x²-4x+5= -(x+5)(x-1)
x² -10x+25=(x-5)²
(x-5)² ≥0
-(x+5)(x-1)
(x-5)² ≤ 0
(x+5)(x-1)
(x-5)(x-5)(x+5)(x-1) ≤0
x=5 x= -5 x=1
+ - + +
---------- -5 ----------- 1 ------------ 5 ---------------
\\\\\\\\\\\\\\
x= 6 + + + + | +
x=2 - - + + | +
x=0 - - + - | -
x= -6 - - - - | +
x∈ (-5; 1)U{5}
D(y)=(-5; 1)U{5}