а)(1+2а)² + 4(1+2а) + 4 = ((1+2а) +2)² = (2а+3)² = (2а+3)•(2а+3).
б) 4с^4-d^2 = (2с²)² - d² = (2с²-d)(2с²+d).
в)16 - x² - 5xb - 20b = (4-х)•(4+х) - 5b(x+4) = (x+4)(4-x-5b).
г) (x-3y)² + 2•(x+2y)•(x-3y) + (x+2y)² = ((x-3y) + (x+2y))² = (х-3у+х+2у)² = (2х-у)² = (2х-у)(2х-у).
а)(1+2а)² + 4(1+2а) + 4 = ((1+2а) +2)² = (2а+3)² = (2а+3)•(2а+3).
б) 4с^4-d^2 = (2с²)² - d² = (2с²-d)(2с²+d).
в)16 - x² - 5xb - 20b = (4-х)•(4+х) - 5b(x+4) = (x+4)(4-x-5b).
г) (x-3y)² + 2•(x+2y)•(x-3y) + (x+2y)² = ((x-3y) + (x+2y))² = (х-3у+х+2у)² = (2х-у)² = (2х-у)(2х-у).