Question

factorise:
a.(y + 4)^3
b.(4y – 2)^3
c.(y – 6)^3
d.(6y + 1)^3

Answer 1

Answer: a.(y + 4)^3 = y^3+4^3+3(y)(4)(y+4)

= y^3+64+12y(y+4)

= y^3+64+12y^2+48y

= y^3+12y^2+48y+64

b.(4y – 2)^3 = (4y)^3-(2)^3-3(4y)(2)(4y-2)

= 64y^3-8-24y(4y-2)

= 64y^3-8-96y^2+48y

= 64y^3-96y^2+48y-8

c.(y – 6)^3 = y^3-6^3-3(y)(6)(y-6)

=y^3-216-18y(y-6)

= y^3-216-18y^2+108y

=y^3-18y^2+108y-216

d.(6y + 1)^3 = (6y)^3+1^3+3(6y)(1)(6y+1)

= 216y^3+1+18y(6y+1)

= 216y^3+1+108y^2+18y

= 216y^3+108y^2+18y+1