# Thread: Need help with algebra on a proof.

1. ## Need help with algebra on a proof.

https://imgur.com/XtBDx8l

When they are constructing the proof working it out, how do they get that 2(q-50) is greater than or equal to 2? Now i understand everything else besides them getting the result that it is greater than or equal to 2.

2. ## Re: Need help with algebra on a proof.

given that $(q-50)$ is a positive integer, i.e. $(q-50)\geq 1$

it's pretty trivial that $2(q-50) \geq 2$

3. ## Re: Need help with algebra on a proof.

Thanks Romsek.. had induction lecture today. Then set theory thursday then first midterm next tuesday.