\( x = \pm 2 \): \( 9(4) = 36 \Rightarrow 25y^2 = 189 \Rightarrow y^2 = 7.56 \) → no
Related Articles
- For each \( x \), check if \( 225 - 9x^2 \) is divisible by 25 and the result for \( y^2 \) is a perfect square.
- \( x = 0 \): \( 9(0) + 25y^2 = 225 \Rightarrow y^2 = 9 \Rightarrow y = \pm 3 \) → 2 points
- \( x = \pm 1 \): \( 9(1) = 9 \Rightarrow 25y^2 = 216 \Rightarrow y^2 = 8.64 \) → not integer
- \( x = \pm 3 \): \( 9(9) = 81 \Rightarrow 25y^2 = 144 \Rightarrow y^2 = 5.76 \) → no
- \( x = \pm 4 \): \( 9(16) = 144 \Rightarrow 25y^2 = 81 \Rightarrow y^2 = 3.24 \) → no
- \( x = \pm 5 \): \( 9(25) = 225 \Rightarrow 25y^2 = 0 \Rightarrow y = 0 \) → 2 points
