Here i have part of a question which im unsure about.

Ive been given this: x^2 + 2x(m+1) + (m-3)(m+1) and i have to add the two factors.

How should i go about it?

2. Originally Posted by steph_r
Here i have part of a question which im unsure about.

Ive been given this: x^2 + 2x(m+1) + (m-3)(m+1) and i have to add the two factors.

How should i go about it?

$\displaystyle x^2 + 2x(m+1) + (m-3)(m+1)$

Factorise.

$\displaystyle x^2 + (m+1)(2x + (m - 3))$

Is this what you meant?

3. Originally Posted by janvdl
$\displaystyle x^2 + 2x(m+1) + (m-3)(m+1)$

Factorise.

$\displaystyle x^2 + (m+1)(2x + (m - 3))$

Is this what you meant?
In the answers it came up with 2m - 2 i.e the coefficient of x ???

4. Originally Posted by steph_r
Here i have part of a question which im unsure about.

Ive been given this: x^2 + 2x(m+1) + (m-3)(m+1) and i have to add the two factors.

How should i go about it?

$\displaystyle Let (m+1) = k$

$\displaystyle x^2 + 2xk + (m - 3)k$

But:
$\displaystyle m - 3 = (m + 1) - 4$

$\displaystyle x^2 + 2xk + (k - 4)k$

$\displaystyle x^2 + 2xk + k^2 - 4k$

$\displaystyle x^2 + 2x(k - 2) + k^2$

But:
$\displaystyle k = m+1$

$\displaystyle x^2 + 2x(m + 1 - 2) + (m + 1)^2$

$\displaystyle x^2 + 2x(m - 1) + (m + 1)^2$

$\displaystyle x^2$ + x(2m - 2) + $\displaystyle (m + 1)^2$

Is this what you wanted?