# Help with Example

• August 9th 2013, 02:44 AM
stephenNW
Help with Example
Hi :)

I am a little stuck with working through this example. In the picture below I understand how to work through down to the red box but I am not sure how to get from the red box to the yellow one.

Could someone explain the steps as simply as possible to me please?
Attachment 28958

Thank you for any help :)
• August 9th 2013, 03:09 AM
TeM
Re: Help with Example
\begin{aligned}(2-\lambda)\lambda(1+\lambda)-(1+\lambda)&=(1+\lambda)\left[(2-\lambda)\lambda-1\right]\\&=(1+\lambda)\left(2\lambda-\lambda^2-1\right)\\&=-(1+\lambda)\left(1-2\lambda+\lambda^2\right)\\&=-(1+\lambda)(1-\lambda)^2\end{aligned}
Ok? (Wink)