1)25x²- 10xу + y² = (5х)² - 2 × 5х × у² = (5 - у)² = (5 - у) × (5 - у)
2)16x²+24xy+9y² = (4х)² + 2 × 4х × 3у + (3у)² = (4х + 3у)² = (4х + 3у) × (4х + 3у)
3)49-x² = 7² - х² = (7 - х) × (7 + х)
4)b²-0,0001a⁴ = b² - (0,01²)² = (b - 0,01²) × (b + 0,01²)
5)16-a⁴ = 4² - (a²)² = (4 - a²) × (4 + a²)