If positive real numbers x, y satisfy 1 / (x + 1) + 9 / y = 1, then the minimum value of X + y is

If positive real numbers x, y satisfy 1 / (x + 1) + 9 / y = 1, then the minimum value of X + y is

1/(x+1)+9/y=1
(y+9*(x+1))/((x+1)y)=1
y+9x+9=xy+y
xy=9(x+1)
y=9(1+1/x)
x+y=x+9/x+9=x+9/x+6+3
=(radical (x) + 3 / radical (x)) ^ 2 + 3
Minimum = 3

If the argument principal value of complex number 3-4i is a, then the argument principal value of complex number 6-8i is a

Because 6-8i = 2 * (3-4i),
So the main value of the radiation angle is still a

Find the range of complex number
The complex z = 3 + AI, and | Z-2 | ≤ 2

z-2=1+ai
| z-2 |=|1+ai|=(1^2+a^2)^(1/2)≤2
The solution is: √ 3 ≤ a ≤√ 3

Given that the value of algebraic formula 2-x / - 4 is a non complex number, then the value range of X is____ . as the title

x>=2