№2. 1) 8x² + 16xy + 8y²; 2)-2a² + 24ab – 72b²; 3) -1263-1262 – 3b; 4) 48m³n - 72m²n + 27mn.

1) \[ 8x^2 + 16xy + 8y^2 = 8(x^2 + 2xy + y^2) = 8(x + y)^2. \]

2) \[ -2a^2 + 24ab - 72b^2 = -2(a^2 - 12ab + 36b^2) = -2(a - 6b)^2. \]

3) \[ -12b^3 - 12b^2 - 3b = -3b(4b^2 + 4b + 1) = -3b(2b + 1)^2. \]

4) \[ 48m^3n - 72m^2n + 27mn = 3mn(16m^2 - 24m + 9) = 3mn(4m - 3)^2. \]