Помогите с номером 896

а)...................

a) a^2(a+1)–(a+1)=(a+1)(a^2–1)=
=(a+1)(a+1)(a–1)=(a+1)^2•(a–1)

б) (b^2–a^2)–c(b–a)=(b–a)(b+a)–c(b–a)=(b–a)(b+a–c)

в) (ab^2–ad^2)+(cd^2–b^2c)=
= a(b^2–d^2)–c(b^2–d^2)=
= (b^2–d^2)(a–c)

г) (x^2y^2–y^2)+(1–x^2)=y^2(x^2–1)–(x^2–1)=(x^2–1)(y^2–1)