Answer:
x = 9
Step-by-step explanation:
[tex]3-\sqrt{x}=0\\\\\text{Domain:}\ x\geq0\\\\3-\sqrt{x}=0\qquad\text{add}\ \sqrt{x}\ \text{to both sides}\\\\3=\sqrt{x}\to\sqrt{x}=3\\\\\text{Use the de}\text{finition of a square root:}\ \sqrt{a}=b\iff b^2=a\\\\\sqrt{x}=3\iff x=3^2\\\\x=9[/tex]
