When taking square roots, you can't take square roots of negative roots of negative numbers. So, what will work for the domain of u(x) is what makes u(x) zero or more. We can make an inequality for that.
u(x) ≥ 0.

9x + 27 ≥ 0 by squaring both sides
9x ≥ -27
x ≥ -3
So the domain of the function is when x ≥ -3 is true.
Input is 4.
Process machine:
Input > - 7 > ÷ 3 > Output
Solve:
(Input) 4 - 7 = <u>-3</u>
<u>-3</u> ÷ 3 = <u>-1 </u>(Output)
Input = 4
Output = -1
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To generate the equation we set up the factors
(x+3) * (x-1) * (x-2) which equals
x^2 + 2x -3 * (x-2)
x^3 +2x^2 -3x -2x^2 -4x +6 equals
x^3 -3x -4x +6 which equals
x^3 -7x +6