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

3663 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations: 2x + 3y = 28 and x + y = 11


Find the equation of the straight line joining points (-1, -4) and (2, 5)


What is Pythagoras' Theorem and how do I use it?


What is the equation of the tangent of the circle x^2+y^2=25 at the point (3,4)


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