The equation of a circle is: (x - h)² + (y - k)² = radius² where (h, k) is the center. Now just plug in your given information and simplify.
(x - 2)² + (y - 0)² = 9²
Your equation is:
(x - 2)² + y² = 81
Isolate the y for both questions. Note that what you do to one side, you do to the other. Do the opposite of PEMDAS.
First question: x - 5y ≥ 3
First, subtract x from both sides
x (-x) - 5y ≥ 3 (-x)
-5y ≥ -x + 3
Divide -5 from both sides. Note that when you divide by a negative number, you flip the equation.
(-5y)/-5 ≥ (-x + 3)/-5
y ≤ (-x + 3)/-5
y ≤ x/5 - 0.6
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Do the same for the second one. Subtract x from both sides
x + y < 0
x (-x) + y < 0 (-x)
y < - x
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