Write 2x^2 + 6x + 6 in the form a(x^2 + b) + c by completing the square.

2x2 + 6x + 62(x2 + 3x + 3) => Factor out 4 from each term so the x2 term of the quadratic has 1 for a coefficient.2[(x + 3/2)2 - d + 3] => Here, we've divided 3x by 2; this coefficient becomes b. When you expand the internal bracket however, you will be left with an additional term. This term is d. We don't want this term, so we subtract this from the quadratic.(x + 3/2)2 = (x + 3/2)(x + 3/2) => Don't make the mistake of just squaring each individual term!= x2 + 3x + 9/4 => 9/4 = d2[(x + 3/2)2 + 3/4] => 3 - 9/4 = 3/4Therefore the final answer is...2(x + 3/2)2 + 3/2(Expand the final term back out so you know you have the right answer.)

II
Answered by Iffshah I. Maths tutor

3368 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A different pattern is made using 20 straight lines and 16 arcs. The straight lines and arcs are made of metal. 20 straight lines cost £12 and the cost of one straight line: cost of one arc = 2:3. Work out the total cost of metal in the pattern.


A bag contains red discs, white discs and blue discs. 1/6 of the discs are red, 1/4 of the discs are blue. What is the smallest possible number of white discs?


Work Out (2+11/15 )-(1+1/3)


Express 3x^2+18x-1 in the form a(x+b)^2 +c


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:

© 2026 by IXL Learning