x² – 8x + 16
x⁴ + 6x² + 9
25x⁶y² – 100x³y + 100
4x² – 24xy + 36y²
x² + 6x + 9
(x – 4)²
(5x³y – 10)²
(2x – 6y)²
(x² + 3)²
(x + 3)²