(x+7)(5х-4)-(x+7)(4x-3) = (x+7)((5х-4)-(4x-3)) = (x+7)(5х-4-4x+3)=(x+7)(x-1)
х²(х+4)-20х(х+4)+100(х+4)=(x+4)(x²-20x+100)=(x+4)(x-10)²
a³-125y³ = (a-5y)(a²+5ay+25y²)
(x+7)(5х-4)-(x+7)(4x-3) = (x+7)((5х-4)-(4x-3)) = (x+7)(5х-4-4x+3)=(x+7)(x-1)
х²(х+4)-20х(х+4)+100(х+4)=(x+4)(x²-20x+100)=(x+4)(x-10)²
a³-125y³ = (a-5y)(a²+5ay+25y²)