Expand and simplify (n + 2)^3 − n^3.

Expand and simplify (+ 2)3 − n3.
Write out the brackets in full:(+ 2)(+ 2)(+ 2) − n3
Use F.O.I.L. (First, Outer, Inner, Last) on first two sets of brackets:(n2+ 2n + 2n + 4)(+ 2) - n3
Simplify by combining like terms (2n + 2n = 4n):(n2+ 4n + 4)(+ 2) - n3
Multiply each term in first set of brackets by each term in second set of brackets:(n3+ 4n2 + 4n + 2n2 + 8n + 8) - n3
As we're not multiplying anything more, the brackets can go:n3+ 4n2 + 4n + 2n2 + 8n + 8 - n3
Simplify by combining like terms (n3 terms cancel, 4n2 + 2n2= 6n2, 4n + 8n = 12n):6n2 + 12n + 8

DC
Answered by Dominic C. Maths tutor

5006 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

How do I differentiate (e^(2x)+1)^3?


A curve has equations: x=2sin(t) and y=1-cos(2t). Find dy/dx at the point where t=pi/6


Prove: (1-cos(2A))/sin(2A) = tan(A)


Prove by induction that the nth triangle number is given by n(n+1)/2


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning