# Math Help - Help with Example

1. ## 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?

Thank you for any help

2. ## 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?