You are Here: Home >< Maths

1. Hi! Can anyone help me with this problem? :

Write in completed square form: 2x²+4x+6

Thanks!
2. (Original post by Aegyst)
Hi! Can anyone help me with this problem? :

Write in completed square form: 2x²+4x+6

Thanks!
First take out a factor of 2:

= 2(x^2 + 2x + 3)

Then complete the square for x^2 + 2x + 3.

Please post your working if you're not sure. If you don't know how to complete the square for x^2 + 2x + 3 then let us know.
3. (Original post by Aegyst)
Hi! Can anyone help me with this problem? :

Write in completed square form: 2x²+4x+6

Thanks!
Whenever you complete the square, the coefficient of the x^2 term must ALWAYS be one. You can do this by taking out a factor of two from the whole equation, then after that you will be left with 2(x^2+2x+3). Then complete the square on x^2+2x+3
4. (Original post by Notnek)
First take out a factor of 2:

= 2(x^2 + 2x + 3)

Then complete the square for x^2 + 2x + 3.

Please post your working if you're not sure. If you don't know how to complete the square for x^2 + 2x + 3 then let us know.
Could you please write down the working? I still don't get it... Thanks.
5. (Original post by jaspreetb)
Whenever you complete the square, the coefficient of the x^2 term must ALWAYS be one. You can do this by taking out a factor of two from the whole equation, then after that you will be left with 2(x^2+2x+3). Then complete the square on x^2+2x+3
Could you give me the step-by-step working? I don't get it, actually.
Thanks, by the way!
6. (Original post by Aegyst)
Could you please write down the working? I still don't get it... Thanks.
Sorry we can't give full solutions.

Can you please show us what you've tried? Do you know how to complete the square for (x^2 + 2x + 3)?
7. (Original post by Notnek)
Sorry we can't give full solutions.

Can you please show us what you've tried? Do you know how to complete the square for (x^2 + 2x + 3)?
Is this correct? :

x²+2x+1 -3+1
(x+1)² -2
(x+1)²+2
8. (Original post by Aegyst)
Is this correct? :

x²+2x+1 -3+1
(x+1)² -2
(x+1)²+2
That's right.

So 2(x^2 + 2x + 3)

is just going to be 2 x this. So you get:

2[(x+1)²+2]

Can you expand this to finish it off (i.e. multiply both terms by 2).

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 9, 2018
Today on TSR

### A level Maths discussions

Find out how you've done here

### 1,954

students online now

Exam discussions

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams