a)
б)
в)
а)-
б)7а^2-14ab+7b^2=a^2-2ab+b^2=(a-b)^2
в)16-y^4
замена:
y^2=t
16-t^2=(4+t)(4-t)=(4+y^2)(4-y^2)=(4+y^2)((2-y)(2+y))
a)
б)
в)
а)-
б)7а^2-14ab+7b^2=a^2-2ab+b^2=(a-b)^2
в)16-y^4
замена:
y^2=t
16-t^2=(4+t)(4-t)=(4+y^2)(4-y^2)=(4+y^2)((2-y)(2+y))